nonpolar molecule
[ /nɑːnpˈɑːlər ˈmɑləˌkjul/ ]
非极性分子
📖 定义
A molecule that lacks a net electric charge or dipole moment due to equal sharing of electrons or symmetrical molecular geometry, making it hydrophobic.
polar molecule
[ /ˈpoʊlər ˈmɑləˌkjul/ ]
极性分子
📖 定义
A molecule (such as water) with an uneven distribution of charges in different regions of the molecule, resulting in partially positive and partially negative poles.
hydrogen bond
[ /ˈhaɪdrəʤən bɑnd/ ]
氢键
📖 定义
A weak bond formed between a partially positive hydrogen atom and a partially negative atom, like oxygen or nitrogen, in different molecules or within a large molecule.
cohesion
[ /koʊˈhiʒən/ ]
内聚力
📖 定义
The attraction between molecules of the same substance, often seen in water due to hydrogen bonding.
adhesion
[ /æˈdhiʒən/ ]
粘附力
📖 定义
The attraction between molecules of different substances, such as water adhering to plant cell walls.
surface tension
[ /ˈsərfəs ˈtɛnʃən/ ]
表面张力
📖 定义
The cohesive forces at the surface of a liquid that allow it to resist external forces and form a "skin."
specific heat / heat capacity
[ /spɪˈsɪfɪk hit / hit kəˈpæsɪti/ ]
比热容
📖 定义
The amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius.
heat of vaporization
[ /hit əv veɪpərəˈzeɪʃən/ ]
汽化热 / 气化潜热
📖 定义
The amount of heat required to convert one gram of a liquid into vapor without a temperature change.
boiling point
[ /ˈbɔɪlɪŋ pɔɪnt/ ]
沸点
📖 定义
The temperature at which the vapor pressure of a liquid equals the external atmospheric pressure, requiring substantial thermal energy to break intermolecular hydrogen bonds in water.
hydrophilic
[ /ˌhaɪdrəˈfɪlɪk/ ]
亲水的
📖 定义
Substances that interact well with water, often due to polar or charged properties.
hydrophobic
[ /ˌhaɪdrəˈfoʊbɪk/ ]
疏水的
📖 定义
Substances that repel water, typically nonpolar and unable to form hydrogen bonds.
organic molecule
[ /ɔrˈgænɪk ˈmɑləˌkjul/ ]
有机分子
📖 定义
A chemical compound that contains carbon atoms covalently bonded to hydrogen and often other elements such as oxygen, nitrogen, and phosphorus.
macromolecule
[ /ˌmækroʊˈmɑːlɪkjuːl/ ]
生物大分子
📖 定义
A giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction; includes carbohydrates, lipids, proteins, and nucleic acids.
monomer
[ /ˈmɑnəmər/ ]
单体
📖 定义
A small molecule that can bind chemically to form larger molecules.
polymer
[ /ˈpɑləmər/ ]
多聚体 / 聚合物
📖 定义
A large molecule composed of repeating monomeric units linked by covalent bonds.
dehydration reaction / dehydration synthesis / condensation
[ /ˌdihaɪˈdreɪʃən riˈækʃən / ˌdihaɪˈdreɪʃən ˈsɪnθəsɪs / ˌkɑːndɛnˈseɪʃən/ ]
脱水缩合反应
📖 定义
A chemical reaction in which two molecules are joined by covalent bonds with the removal of a water molecule.
hydrolysis
[ /haɪˈdrɑːləsɪs/ ]
水解反应
📖 定义
A chemical reaction in which water is used to break bonds between molecules.
carbohydrates
[ /ˌkɑrboʊˈhaɪdreɪts/ ]
碳水化合物 / 糖类
📖 定义
Organic compounds composed of carbon, hydrogen, and oxygen, primarily used for energy storage and structural purposes.
monosaccharide
[ /ˌmɑːnoʊˈsækəraɪd/ ]
单糖
📖 定义
The simplest form of carbohydrate, consisting of a single sugar molecule.
glucose
[ /ˈɡluːkoʊs/ ]
葡萄糖
📖 定义
A six-carbon monosaccharide (hexose) with the molecular formula C6H12O6; serves as the primary substrate for cellular respiration and a monomer for glycogen, starch, and cellulose.
galactose
[ /ɡəˈlæktoʊs/ ]
半乳糖
📖 定义
A six-carbon aldose monosaccharide that is a stereoisomer of glucose; combines with glucose via a beta-1,4-glycosidic bond to form the disaccharide lactose.
fructose
[ /ˈfrʊktoʊs/ ]
果糖
📖 定义
A six-carbon keto-hexose monosaccharide found commonly in fruits and honey; combines with glucose via an alpha-1,beta-2-glycosidic bond to form sucrose.
disaccharide
[ /daɪˈsækəraɪd/ ]
二糖
📖 定义
A carbohydrate composed of two monosaccharides linked by a glycosidic bond.
maltose
[ /ˈmɔːltoʊs/ ]
麦芽糖
📖 定义
A disaccharide composed of two glucose molecules linked by an alpha-1,4-glycosidic bond; produced during the enzymatic breakdown of starch.
sucrose
[ /ˈsuːkroʊs/ ]
蔗糖
📖 定义
A common disaccharide (table sugar) consisting of one glucose and one fructose molecule linked by a glycosidic bond; major transport form of sugar in plants.
lactose
[ /ˈlæktoʊs/ ]
乳糖
📖 定义
A disaccharide composed of one galactose and one glucose unit joined by a beta-1,4-glycosidic linkage; the primary carbohydrate found in mammalian milk.
polysaccharide
[ /ˌpɑːliˈsækəraɪd/ ]
多糖
📖 定义
A complex carbohydrate consisting of long chains of monosaccharide units.
starch
[ /stɑrʧ/ ]
淀粉
📖 定义
A storage polysaccharide in plants consisting entirely of glucose monomers linked by alpha-1,4 and alpha-1,6 glycosidic bonds (composed of amylose and amylopectin).
glycogen
[ /ˈɡlaɪkədʒən/ ]
糖原
📖 定义
An extensively branched storage polysaccharide of glucose found in animal liver and muscle tissues; hydrolyzed to release glucose when metabolic demand increases.
cellulose
[ /ˈsɛljʊloʊs/ ]
纤维素
📖 定义
A structural polysaccharide of plant cell walls consisting of straight, unbranched beta-1,4-linked glucose chains bundled into rigid, insoluble microfibrils.
lipids
[ /lˈɪpədz/ ]
脂质 / 脂类
📖 定义
A group of hydrophobic organic molecules, including fats, oils, and steroids, that are used for energy storage and cell membrane structure.
fatty acid
[ /ˈfæti ˈæsəd/ ]
脂肪酸
📖 定义
A carboxylic acid with a long hydrocarbon chain, a key component of lipids.
hydrocarbon chain
[ /ˌhaɪdroʊˈkɑrbən ʧeɪn/ ]
碳氢链
📖 定义
A nonpolar chain of covalently bonded carbon and hydrogen atoms, such as the fatty acid tail of lipids, that is hydrophobic and energy-rich.
unsaturated fatty acid
[ /ənˈsæʧərˌeɪtɪd ˈfæti ˈæsəd/ ]
不饱和脂肪酸
📖 定义
A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail, creating kinks that prevent tight packing and keeping them liquid at room temperature.
saturated fatty acid
[ /ˈsæʧərˌeɪtɪd ˈfæti ˈæsəd/ ]
饱和脂肪酸
📖 定义
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, maximizing the number of hydrogen atoms attached and typically solid at room temperature.
glycerol
[ /ˈglɪsərˌoʊl/ ]
甘油
📖 定义
A three-carbon alcohol with three hydroxyl (-OH) groups that forms the covalent backbone of triglycerides and phospholipids through ester linkages.
triglyceride
[ /traɪˈɡlɪsəraɪd/ ]
甘油三酯
📖 定义
A lipid molecule made up of one glycerol and three fatty acid chains.
phospholipid
[ /ˌfɑːsfoʊˈlɪpɪd/ ]
磷脂
📖 定义
A lipid containing a phosphate group and two fatty acid tails, essential for cell membranes.
phosphate group
[ /ˈfɑsfeɪt grup/ ]
磷酸基团
📖 定义
A functional group (-PO4^2-) consisting of a phosphorus atom covalently bonded to four oxygen atoms; critical in energy transfer (ATP), nucleic acid backbones, and phospholipid membranes.
phospholipid bilayer
[ /ˌfɑːsfoʊˈlɪpɪd ˈbaɪleɪər/ ]
磷脂双分子层
📖 定义
The double-layered structure of cell membranes formed by phospholipids, with hydrophilic heads outward and hydrophobic tails inward
steroid
[ /stərɔɪd/ ]
类固醇 / 固醇类
📖 定义
A type of lipid with a characteristic four-ring structure, functioning as hormones or membrane components.
cholesterol
[ /kəˈlɛstərˌɔl/ ]
胆固醇
📖 定义
A steroid that is a key component of cell membranes and a precursor for other steroid hormones.
hormone
[ /ˈhɔrˌmoʊn/ ]
激素 / 荷尔蒙
📖 定义
A secreted signaling molecule in multicellular organisms that travels in body fluids to act on specific target cells to coordinate physiology and behavior.
protein
[ /ˈproʊˌtin/ ]
蛋白质
📖 定义
A macromolecule composed of amino acids, essential for various biological functions including enzymes, structure, and signaling.
amino acid
[ /əˈminoʊ ˈæsəd/ ]
氨基酸
📖 定义
The building block of proteins, consisting of an amino group, a carboxyl group, and a unique side chain.
R group
[ /ɑr grup/ ]
R基 (侧链基团)
📖 定义
The variable side chain attached to the alpha-carbon of an amino acid that confers its distinctive chemical properties (polar, nonpolar, acidic, or basic).
side chain
[ /saɪd ʧeɪn/ ]
侧链
📖 定义
Alternative term for the R group of an amino acid; determines the tertiary folding pattern and chemical reactivity of a protein.
backbone
[ /ˈbækˌboʊn/ ]
主链 / 骨架
📖 定义
The repeating structural chain of a polymer, such as the sugar-phosphate chain in nucleic acids or the N-C-C chain in polypeptide backbones.
peptide bond
[ /ˈpɛpˌtaɪd bɑnd/ ]
肽键
📖 定义
A covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
polypeptide
[ /pˌɑːliːpˈɛptədˌaɪd/ ]
多肽
📖 定义
A chain of amino acids linked by peptide bonds, which folds to form a protein.
amino-end (N-terminus)
[ /ˈæmɪnˌoʊdn/ ]
氨基端 (N端)
📖 定义
The end of a polypeptide chain that terminates with an unbound, free amino group (-NH2 or -NH3+); represents the start of protein synthesis.
carboxyl-end (C-terminus)
[ /kˈɑːrbəklˌɪst/ ]
羧基端 (C端)
📖 定义
The end of a polypeptide chain that terminates with an unbound, free carboxyl group (-COOH or -COO-); represents the terminus where new amino acids are added.
primary structure
[ /ˈpraɪˌmɛri ˈstrəkʧər/ ]
一级结构
📖 定义
The linear sequence of amino acids in a protein.
secondary structure
[ /ˈsɛkənˌdɛri ˈstrəkʧər/ ]
二级结构
📖 定义
Localized folding of a polypeptide into structures like alpha-helices and beta- sheets, stabilized by hydrogen bonds.
alpha-helix (α-helix)
[ /ˈælfəlˌɛkəlz/ ]
α螺旋
📖 定义
A secondary structure of proteins consisting of a coiled polypeptide chain stabilized by hydrogen bonds between the carbonyl oxygen and amide hydrogen four residues apart.
beta-pleated sheet (β-pleated sheet)
[ /bˈiːtəplˌeɪtəd ʃit/ ]
β折叠
📖 定义
A secondary protein structure in which two or more parallel or antiparallel polypeptide strands are held together by hydrogen bonds between backbone atoms.
tertiary structure
[ /ˈtərʃəri ˈstrəkʧər/ ]
三级结构
📖 定义
The overall three-dimensional shape of a protein formed by interactions between side chains.
disulfide bridge
[ /dɪsˈʌləfˌaɪd brɪʤ/ ]
二硫键
📖 定义
A strong covalent bond formed between the sulfhydryl (-SH) groups of two cysteine residues; stabilizes the tertiary and quaternary structures of proteins.
quaternary structure
[ /kˈwɑtərˌnɛri ˈstrəkʧər/ ]
四级结构
📖 定义
The structure formed when multiple polypeptides interact to form a functional protein.
hemoglobin
[ /ˌhiməˈgloʊbən/ ]
血红蛋白
📖 定义
An iron-containing quaternary protein in red blood cells consisting of two alpha and two beta globin subunits that transports oxygen from lungs to tissues.
denaturation
[ /dɪnˈækjətrˈeɪʃən/ ]
（蛋白质）变性
📖 定义
A process in which a protein loses its native three-dimensional tertiary/secondary structure due to disruption of weak chemical bonds and interactions by heat, extreme pH, or chemical agents, rendering it biologically inactive.
alpha-globin (α-globin)
[ /ˌælfəɡˈɑːlbən/ ]
α珠蛋白
📖 定义
One of the two primary polypeptide subunit types that compose adult hemoglobin, encoded by genes on human chromosome 16.
beta-globin (β-globin)
[ /bɪtˈɑːɡlən/ ]
β珠蛋白
📖 定义
One of the two primary polypeptide subunit types that compose adult hemoglobin, encoded by genes on human chromosome 11; mutated in sickle cell disease.
DNA (deoxyribonucleic acid)
[ /ˈdiˌɛˈneɪ/ ]
脱氧核糖核酸
📖 定义
A double-stranded, helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose and the bases A, T, C, G; stores hereditary information.
nucleic acid
[ /nuˈkleɪɪk ˈæsəd/ ]
核酸
📖 定义
A macromolecule that stores genetic information, such as DNA and RNA.
renaturation
[ /rɪnˈætʃərətˈeɪn/ ]
（蛋白质）复性
📖 定义
The refolding of a denatured, biologically inactive protein back into its native, biologically active three-dimensional conformation upon restoration of physiological conditions.
nucleotide
[ /ˈnuːkliətaɪd/ ]
核苷酸
📖 定义
The building block of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.
deoxyribose
[ /diːˌɑːksɪˈraɪboʊs/ ]
脱氧核糖
📖 定义
The five-carbon pentose sugar found in DNA nucleotides, which lacks a hydroxyl group at the 2' carbon position (contains -H instead of -OH).
ribose
[ /ˈraɪboʊs/ ]
核糖
📖 定义
The five-carbon pentose sugar present in RNA nucleotides and ATP, containing a hydroxyl group (-OH) attached to the 2' carbon position.
nitrogenous base
[ /naɪˈtrɑʤənəs beɪs/ ]
含氮碱基
📖 定义
A nitrogen-containing organic molecule with basic properties that forms the informational component of nucleotides; classified into purines and pyrimidines.
pyrimidine
[ /pˌɪrɪmˈɪdiːn/ ]
嘧啶
📖 定义
A class of nitrogenous bases characterized by a single six-membered carbon-nitrogen ring; includes cytosine (C), thymine (T), and uracil (U).
purine
[ /pʊrˈiːniː/ ]
嘌呤
📖 定义
A class of nitrogenous bases characterized by a fused six-membered and five-membered carbon-nitrogen double ring; includes adenine (A) and guanine (G).
cytosine
[ /ˈsaɪtəsiːn/ ]
胞嘧啶
📖 定义
A pyrimidine nitrogenous base found in both DNA and RNA that forms three hydrogen bonds with guanine during base pairing.
thymine
[ /ˈθaɪmiːn/ ]
胸腺嘧啶
📖 定义
A pyrimidine nitrogenous base found exclusively in DNA that pairs with adenine via two hydrogen bonds.
uracil
[ /ˈjʊrəsɪl/ ]
尿嘧啶
📖 定义
A pyrimidine nitrogenous base found exclusively in RNA that pairs with adenine via two hydrogen bonds during transcription and translation.
adenine
[ /ˈædənɪn/ ]
腺嘌呤
📖 定义
A purine nitrogenous base found in DNA, RNA, and ATP that pairs with thymine in DNA (two hydrogen bonds) and uracil in RNA.
guanine
[ /ˈɡwɑːniːn/ ]
鸟嘌呤
📖 定义
A purine nitrogenous base found in DNA and RNA that forms three hydrogen bonds with cytosine during complementary base pairing.
sugar-phosphate backbone
[ /saɪɡˈʌsprəhˌeɪts ˈbækˌboʊn/ ]
糖-磷酸骨架
📖 定义
The alternating chain of sugar and phosphate units linked by covalent phosphodiester bonds that forms the structural structural sides of a nucleic acid strand.
3' end
[ /ɛnd/ ]
3'端 (3号碳端)
📖 定义
The terminus of a nucleic acid strand terminating in a free hydroxyl group (-OH) attached to the 3' carbon of the terminal pentose sugar.
5' end
[ /ɛnd/ ]
5'端 (5号碳端)
📖 定义
The terminus of a nucleic acid strand terminating in a free phosphate group attached to the 5' carbon of the terminal pentose sugar.
base pairing
[ /beɪs ˈpɛrɪŋ/ ]
碱基互补配对
📖 定义
The specific hydrogen bonding between complementary bases in DNA or RNA （e.g.， A-T or A-U, and G-C）.
base sequence
[ /beɪs ˈsikwəns/ ]
碱基序列
📖 定义
The specific order of nitrogenous bases in a nucleic acid, encoding genetic information.
antiparallel
[ /ˌæntəpˈɑːrələ/ ]
反向平行
📖 定义
The opposite orientation of the two strands in a DNA double helix.
double helix
[ /ˈdəbəl ˈhiːlɪks/ ]
双螺旋
📖 定义
The spiral-shaped structure formed by two strands of DNA held together by base pairing.
prokaryotic cell
[ /proʊˌkæriˈɑːtɪk sɛl/ ]
原核细胞
📖 定义
A cell without a nucleus or membrane-bound organelles, characteristic of bacteria and archaea.
eukaryotic cell
[ /juːˌkæriˈɑːtɪk sɛl/ ]
真核细胞
📖 定义
A cell with a nucleus and membrane-bound organelles, found in plants, animals， fungi,and protists.
bacterium / bacteria
[ /bækˈtɪriəm / bækˈtɪriə/ ]
细菌
📖 定义
Single-celled prokaryotic microorganisms that possess peptidoglycan cell walls, circular DNA, and 70S ribosomes, lacking membrane-bound organelles.
archaea
[ /ɑːrkˈeɪə/ ]
古菌
📖 定义
A domain of single-celled prokaryotes biochemically distinct from bacteria, often inhabiting extreme environments (extremophiles) and having unique ether-linked membrane lipids.
animal
[ /ˈænəməl/ ]
动物
📖 定义
A kingdom of multicellular, heterotrophic eukaryotic organisms that ingest other organisms, lack cell walls, and possess differentiated tissues.
plant
[ /plænt/ ]
植物
📖 定义
A kingdom of multicellular, autotrophic eukaryotic organisms with cellulose cell walls, chloroplasts for photosynthesis, and alternation of generations.
fungus / fungi
[ /ˈfəŋgəs / ˈfənʤaɪ/ ]
真菌
📖 定义
A kingdom of heterotrophic eukaryotes that absorb nutrients from their surroundings via hyphae, possess chitinous cell walls, and act as major decomposers.
protist
[ /prˈoʊtɪst/ ]
原生生物
📖 定义
A diverse, non-monophyletic paraphyletic group of mostly unicellular eukaryotes that are not animals, plants, or fungi (e.g., amoebas, paramecia, algae).
cell membrane / plasma membrane
[ /sɛl ˈmɛmˌbreɪn / ˈplæzmə ˈmɛmˌbreɪn/ ]
细胞膜 / 质膜
📖 定义
A selectively permeable barrier that surrounds the cell, controlling the movement of substances in and out.
cytoplasm
[ /ˈsaɪtəplæzəm/ ]
细胞质
📖 定义
The region of the cell between the plasma membrane and the nucleus, containing organelles and the cytosol.
cytosol
[ /ˈsaɪtəsɑːl/ ]
细胞质基质
📖 定义
The gel-like substance within the cytoplasm where organelles and cellular components are suspended.
nucleus
[ /ˈnukliəs/ ]
细胞核
📖 定义
The membrane-bound organelle that houses the cell's DNA and controls its activities.
membrane-bound organelle
[ /mˌɛmbrəndˈænb ˌɔːrɡənˈɛl/ ]
膜结合细胞器
📖 定义
An organelle enclosed by a lipid bilayer, such as the nucleus, mitochondria, or Golgi apparatus.
nucleoid
[ /nˈuːklˌɔɪd/ ]
拟核
📖 定义
The region in a prokaryotic cell where the DNA is located, not enclosed by a membrane.
organelle
[ /ˌɔːrɡənˈɛl/ ]
细胞器
📖 定义
A specialized structure within a cell that performs specific functions.
fluid mosaic model
[ /fluɪd moʊˈzeɪɪk ˈmɑdəl/ ]
流动镶嵌模型
📖 定义
A model describing the structure of the plasma membrane as a flexible bilayer with embedded proteins.
compartmentalization
[ /kˌɑːmpˌɑːrtəmpʃənˈɛtləsniː/ ]
区室化
📖 定义
The organization of cellular activities into specialized, membrane-bound compartments.
glycoprotein
[ /ɡlˈaɪkrəpˌɔɪtn/ ]
糖蛋白
📖 定义
A membrane or secretory protein covalently bonded to one or more carbohydrate oligosaccharide chains, crucial for cell-cell recognition and immune signaling.
glycolipid
[ /ɡlˈaɪkəlˌaɪds/ ]
糖脂
📖 定义
A lipid molecule covalently attached to one or more carbohydrate chains, embedded in the plasma membrane and involved in cell recognition and membrane stability.
cell-cell recognition
[ /sˈɛltʃˌɛl ˌrɛkɪgˈnɪʃən/ ]
细胞间识别
📖 定义
The ability of a cell to distinguish neighboring cells by binding to surface molecules (often glycoproteins or glycolipids) on the extracellular plasma membrane.
intercellular joining
[ /ˌɪntərˈsɛljələr ˈʤɔɪnɪŋ/ ]
细胞间连接
📖 定义
Membrane proteins of adjacent cells that hook together in various junctions (such as tight junctions, gap junctions, or desmosomes) to facilitate adhesion and communication.
selective permeability
[ /səˈlɛktɪv pərˌmiəˈbɪlɪti/ ]
选择透过性
📖 定义
A fundamental property of biological membranes that allows them to regulate the passage of substances across them, permitting certain molecules to enter or exit while excluding others.
passive transport
[ /ˈpæsɪv ˈtrænspɔrt/ ]
被动运输
📖 定义
The movement of substances across a membrane without the use of energy, down their concentration gradient.
simple diffusion
[ /ˈsɪmpəl dɪfˈjuʒən/ ]
简单扩散 / 自由扩散
📖 定义
The movement of molecules directly across the membrane down their concentration gradient.
facilitated diffusion
[ /fəˈsɪləˌteɪtɪd dɪfˈjuʒən/ ]
易化扩散 / 协助扩散
📖 定义
The passive movement of molecules across a membrane through transport proteins.
transport protein
[ /ˈtrænspɔrt ˈproʊˌtin/ ]
转运蛋白
📖 定义
A transmembrane protein (such as a channel or carrier) that assists a specific polar molecule or ion in crossing the hydrophobic plasma membrane.
channel protein
[ /ˈʧænəl ˈproʊˌtin/ ]
通道蛋白
📖 定义
A transmembrane transport protein that provides a hydrophilic passageway allowing specific water-soluble molecules or ions to diffuse rapidly across the hydrophobic lipid bilayer.
carrier protein
[ /ˈkɛriər ˈproʊˌtin/ ]
载体蛋白
📖 定义
A transport protein that binds specific solute molecules and undergoes conformational changes to shuttle them across the biological membrane down or against their concentration gradient.
osmosis
[ /ɑːzˈmoʊsɪs/ ]
渗透作用
📖 定义
The diffusion of water across a selectively permeable membrane from a region of lower solute concentration to higher solute concentration.
aquaporin
[ /ˈækwəpˌɔːrn/ ]
水通道蛋白
📖 定义
A specialized channel protein in the plasma membrane that facilitates the rapid, selective passage of water molecules by osmosis.
hypotonic
[ /hˌaɪpətˈɑːnɪk/ ]
低渗的
📖 定义
A solution with a lower solute concentration compared to another, causing water to enter a cell.
hypertonic
[ /ˌhaɪpərˈtɑnɪk/ ]
高渗的
📖 定义
A solution with a higher solute concentration compared to another, causing water to leave a cell.
isotonic
[ /ˌaɪsəˈtɑnɪk/ ]
等渗的
📖 定义
A solution with the same solute concentration as another, resulting in no net water movement.
osmoregulation
[ /ˌɑːzmoʊˌrɛɡjʊˈleɪʃən/ ]
渗透调节
📖 定义
The process by which organisms maintain water and solute balance within their bodies or cells.
water potential
[ /ˈwɔtər pəˈtɛnʃəl/ ]
水势
📖 定义
A measure of the potential energy in water, determining the direction of its movement.
pressure potential
[ /ˈprɛʃər pəˈtɛnʃəl/ ]
压力势
📖 定义
A component of water potential that represents the physical pressure exerted on a solution; positive in turgid plant cells, negative under tension (transpiration).
primary active transport
[ /ˈpraɪˌmɛri ˈæktɪv ˈtrænspɔrt/ ]
初级主动运输
📖 定义
Active transport that directly uses energy, typically from ATP, to move substances.
solute potential
[ /sˈoʊluːt pəˈtɛnʃəl/ ]
溶质势
📖 定义
A component of water potential that is directly proportional to the molarity of a solution and is always zero or negative; reduces water potential as solute concentration rises.
active transport
[ /ˈæktɪv ˈtrænspɔrt/ ]
主动运输
📖 定义
The movement of substances across a membrane against their concentration gradient, requiring energy.
secondary active transport
[ /ˈsɛkənˌdɛri ˈæktɪv ˈtrænspɔrt/ ]
次级主动运输
📖 定义
Active transport that uses the energy from an existing gradient established by primary active transport.
Na+/K+ pump (Na+/K+ ATPase)
[ /nɑ / keɪ pəmp nɑ / keɪ ˈætpˌeɪs/ ]
钠钾泵
📖 定义
An electrogenic transmembrane transport protein that hydrolyzes ATP to actively pump 3 Na+ out of the cell and 2 K+ into the cell against their concentration gradients.
endocytosis
[ /ˌɛndoʊsaɪˈtoʊsɪs/ ]
胞吞作用
📖 定义
The process of taking substances into the cell by engulfing them in vesicles.
exocytosis
[ /ˌɛksoʊsaɪˈtoʊsɪs/ ]
胞吐作用
📖 定义
The process of expelling substances from the cell by vesicles fusing with the plasma membrane.
vesicle
[ /ˈvɛsɪkəl/ ]
囊泡 / 小泡
📖 定义
A small, membrane-bound sac used for transport or storage within a cell.
nuclear envelope
[ /ˈnukliər ˈɛnvəˌloʊp/ ]
核膜
📖 定义
A double membrane perforated with protein-lined nuclear pores that encloses the nucleus, separating genetic material from the cytoplasm in eukaryotic cells.
nucleolus
[ /njuːˈkliːələs/ ]
核仁
📖 定义
A dense region inside the non-dividing eukaryotic nucleus where ribosomal RNA (rRNA) is synthesized and assembled with ribosomal proteins into ribosome subunits.
nuclear pore
[ /ˈnukliər pɔr/ ]
核孔
📖 定义
A large protein complex spanning the double membrane of the nuclear envelope that regulates molecular trafficking (mRNA, proteins) between nucleus and cytoplasm.
chromatin
[ /ˈkroʊmətɪn/ ]
染色质
📖 定义
The complex of DNA and proteins in a loose form that forms chromosomes within the nucleus.
ribosome
[ /ˈraɪbəsoʊm/ ]
核糖体
📖 定义
A cellular structure that synthesizes proteins by translating messenger RNA.
large subunit
[ /lɑrʤ səbˈiːnɪt/ ]
大亚基
📖 定义
The larger of the two ribonucleoprotein complexes forming a functional ribosome; catalyzes peptide bond formation at its peptidyl transferase center.
small subunit
[ /smɔl səbˈiːnɪt/ ]
小亚基
📖 定义
The smaller ribonucleoprotein ribosomal subunit that binds mRNA and mediates base pairing between mRNA codons and tRNA anticodons.
ribosomal RNA (rRNA)
[ /ˌraɪbəˈsoʊməl ˌɑːr.ɛnˈeɪ/ ]
核糖体RNA
📖 定义
RNA molecules that, together with proteins, make up ribosomes; some rRNAs have catalytic enzymatic activity (ribozymes) in peptide bond synthesis.
free ribosome
[ /fri ˈraɪbəsoʊm/ ]
游离核糖体 (悬浮核糖体)
📖 定义
A ribosome suspended in the cytosol that synthesizes proteins destined to function primarily within the cytoplasm of the cell.
attached ribosome
[ /əˈtæʧt ˈraɪbəsoʊm/ ]
附着核糖体 (黏附核糖体)
📖 定义
A ribosome bound to the cytosolic surface of the rough endoplasmic reticulum or outer nuclear membrane, synthesizing proteins destined for insertion into membranes, organelle packaging, or secretion.
smooth endoplasmic reticulum (smooth ER)
[ /smuð ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ]
滑面内质网
📖 定义
The portion of the ER without ribosomes, involved in lipid synthesis and detoxification.
endoplasmic reticulum (ER)
[ /ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ]
内质网
📖 定义
A network of membranes involved in protein and lipid synthesis.
rough endoplasmic reticulum (rough ER)
[ /rəf ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ]
粗面内质网
📖 定义
The portion of the ER studded with ribosomes, involved in protein synthesis and modification.
Golgi apparatus (body / complex)
[ /ˈgoʊlʤi ˌæpərˈætəs ˈbɑdi / ˈkɑmplɛks/ ]
高尔基体
📖 定义
A membrane-bound organelle that modifies, sorts, and packages proteins and lipids for transport.
lysosome
[ /ˈlaɪsəsoʊm/ ]
溶酶体
📖 定义
A membrane-bound organelle containing enzymes for digesting macromolecules and recycling cellular components.
hydrolytic enzyme
[ /hˌaɪdrəlˈɪtɪk ˈɛnˌzaɪm/ ]
水解酶
📖 定义
A class of digestive enzymes (such as acid hydrolases in lysosomes) that catalyze the cleavage of chemical bonds by the addition of water molecules.
apoptosis
[ /ˌæpɔpˈtoʊsɪz/ ]
细胞凋亡
📖 定义
Programmed cell death, a controlled process that eliminates unnecessary or damaged cells.
vacuole
[ /ˈvækjuːoʊl/ ]
液泡
📖 定义
A membrane-bound sac used for storage, waste disposal, and maintaining cell pressure.
central vacuole
[ /ˈsɛntrəl ˈvækjuːoʊl/ ]
中央大液泡
📖 定义
A large vacuole in plant cells that stores water and maintains turgor pressure.
mitochondrion / mitochondria
[ /ˌmaɪtəˈkɑːndriən / ˌmaɪtəˈkɑːndriə/ ]
线粒体
📖 定义
The organelle where cellular respiration occurs, producing ATP.
cellular respiration
[ /ˈsɛljələr ˌrɛspərˈeɪʃən/ ]
细胞呼吸
📖 定义
A process that converts glucose into ATP by breaking down organic molecules in the presence of oxygen.
crista / cristae
[ /ˈkrɪstə / ˈkrɪstiː/ ]
线粒体嵴
📖 定义
Infoldings of the inner mitochondrial membrane that house the electron transport chain and ATP synthase complexes, greatly increasing the surface area for ATP production.
mitochondrial matrix
[ /mˌaɪtəkˈɑːndriːəl ˈmeɪtrɪks/ ]
线粒体基质
📖 定义
The fluid-filled compartment enclosed by the inner mitochondrial membrane containing enzymes for the citric acid cycle, mitochondrial DNA, and ribosomes.
intermembrane space
[ /ˌɪntərmbˈɛrən speɪs/ ]
膜间隙
📖 定义
The narrow region between the inner and outer membranes of mitochondria or chloroplasts; serves as a reservoir for accumulated protons during chemiosmosis.
chloroplast
[ /ˈklɔːrəplæst/ ]
叶绿体
📖 定义
The organelle in plant and algal cells where photosynthesis occurs.
photosynthesis
[ /ˌfoʊtoʊˈsɪnθəsɪs/ ]
光合作用
📖 定义
The process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose.
stroma
[ /ˈstroʊmə/ ]
叶绿体基质
📖 定义
The dense fluid within the chloroplast surrounding the thylakoid membranes; site of the Calvin cycle (carbon fixation) and containing chloroplast DNA and ribosomes.
thylakoid
[ /ˈθaɪləkɔɪd/ ]
类囊体
📖 定义
A flattened, membranous sac inside a chloroplast arranged in stacks (grana); its membranes contain chlorophyll and pigments where light-dependent reactions occur.
granum / grana
[ /ˈgrænəm / ˈgrænə/ ]
基粒
📖 定义
A stack of membrane-bound thylakoid discs in chloroplasts where light absorption and photophosphorylation take place.
endosymbiosis hypothesis
[ /ˌɛndoʊsˌaɪəmbˈiːəsəs haɪˈpɑθəsəs/ ]
内共生假说
📖 定义
The theory that mitochondria and chloroplasts originated from free-living prokaryotes engulfed by ancestral eukaryotic cells.
cytoskeleton
[ /sˌaɪtoʊksˈɛlətən/ ]
细胞骨架
📖 定义
A network of protein fibers that provide structural support and enable cell movement.
microtubule
[ /ˈmaɪˌkroʊˈtubjul/ ]
微管
📖 定义
A cylinder-shaped component of the cytoskeleton involved in maintaining cell shape, transport, and division.
microfilament
[ /mˌaɪkroʊfˈiːlməntənt/ ]
微丝
📖 定义
A thin solid helical rod composed of actin protein monomers, forming part of the cytoskeleton and essential for cell motility, muscle contraction, and cytoplasmic streaming.
cilium / cilia
[ /tʃˈɪliːəm / sˈɪliːə/ ]
纤毛
📖 定义
Short, hair-like structures that move fluid or substances across a cell surface or propel the cell.
flagellum / flagella
[ /fləˈʤɛləm / fləˈʤɛlə/ ]
鞭毛
📖 定义
Long, whip-like structures that enable cell movement.
centrosome
[ /ˈsɛntrəsoʊm/ ]
中心体
📖 定义
The microtubule-organizing center of a cell, important in cell division.
centriole
[ /ˈsɛntrioʊl/ ]
中心粒
📖 定义
A cylinder composed of nine triplets of microtubules located in the centrosome of animal cells; involved in organizing the mitotic spindle during cell division.
cell wall
[ /sɛl wɔl/ ]
细胞壁
📖 定义
A rigid structure surrounding the plasma membrane in plant, fungal, and some prokaryotic cells, providing support and protection.
cellulose
[ /ˈsɛljʊloʊs/ ]
纤维素
📖 定义
A structural polysaccharide of plant cell walls consisting of straight, unbranched beta-1,4-linked glucose chains bundled into rigid, insoluble microfibrils.
plasmodesma / plasmodesmata
[ /plˌæsmədˈoʊsmə / plˌæsməstˈɑːdəm/ ]
胞间连丝
📖 定义
Open channels through the cell walls of adjacent plant cells connecting their cytoplasms and enabling intercellular transport and communication.
second law of thermodynamics
[ /ˈsɛkənd lɔ əv θˌɜːrmədˈiːniːəsk/ ]
热力学第二定律
📖 定义
Energy transformations increase the entropy （disorder） of the universe, and some energy is always lost as heat.
entropy
[ /ˈɛntrəpi/ ]
熵
📖 定义
A thermodynamic measure of the disorder, randomness, or thermal energy unavailable for doing mechanical work in a closed system; tends to increase spontaneously.
Gibbs free energy (G)
[ /gɪbz fri ˈɛnərʤi/ ]
吉布斯自由能
📖 定义
The portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system; a negative change in Gibbs free energy (ΔG < 0) indicates a spontaneous exergonic process.
endergonic reaction
[ /ˌɛndərɡˈɑːnɪk riˈækʃən/ ]
吸能反应
📖 定义
A chemical reaction that requires an input of energy, with products having more energy than reactants.
exergonic reaction
[ /ˌɛɡzrˈɔːdʒɪnæk riˈækʃən/ ]
放能反应
📖 定义
A chemical reaction that releases energy, with products having less energy than reactants.
activation energy
[ /ˌæktəˈveɪʃən ˈɛnərʤi/ ]
活化能
📖 定义
The minimum energy required to initiate a chemical reaction.
active site
[ /ˈæktɪv saɪt/ ]
活性位点
📖 定义
The region of an enzyme where substrates bind and the chemical reaction occurs.
enzyme
[ /ˈɛnˌzaɪm/ ]
酶
📖 定义
A biological catalyst that speeds up chemical reactions by lowering the activation energy.
substrate
[ /ˈsʌbstreɪt/ ]
底物
📖 定义
The specific reactant molecule upon which an enzyme acts and binds at its active site to undergo a catalyzed chemical transformation.
optimal temperature
[ /ˈɑptɪməl ˈtɛmpərəʧər/ ]
最适温度
📖 定义
The specific temperature at which an enzyme's catalytic activity is maximal; deviations above this point can cause thermal denaturation.
optimal pH
[ /ˈɑptɪməl ˈpiˈeɪʧ/ ]
最适pH
📖 定义
The specific pH value at which an enzyme exhibits its maximum reaction velocity; changes in pH alter amino acid ionization at the active site.
allosteric site
[ /ˌæləˈstɛrɪk saɪt/ ]
别构位点 / 变构位点
📖 定义
A site on an enzyme, separate from the active site, where molecules can bind to regulate enzyme activity.
noncompetitive inhibition
[ /ˌnɑnkəmˈpɛtətɪv ˌɪnəˈbɪʃən/ ]
非竞争性抑制
📖 定义
Inhibition where a molecule binds to an allosteric site, reducing enzyme activity without competing with the substrate.
inhibitor
[ /ˌɪnˈhɪbətər/ ]
抑制剂
📖 定义
A substance that reduces or stops the catalytic activity of an enzyme, acting either competitively at the active site or noncompetitively at an allosteric site.
competitive inhibition
[ /kəmˈpɛtɪtɪv ˌɪnəˈbɪʃən/ ]
竞争性抑制
📖 定义
Inhibition where a molecule competes with the substrate for binding to the active site of an enzyme.
coenzyme
[ /koʊˈɛnzaɪm/ ]
辅酶
📖 定义
An organic molecule that assists enzymes in catalyzing reactions, often by transferring electrons or functional groups.
adenosine triphosphate (ATP)
[ /əˈdɛnəsiːn traɪˈfɑːsfeɪt/ ]
三磷酸腺苷
📖 定义
The primary energy carrier in cells, providing energy for various cellular processes.
adenosine diphosphate (ADP)
[ /əˈdɛnəsiːn daɪˈfɑːsfeɪt/ ]
二磷酸腺苷
📖 定义
A lower-energy molecule formed when ATP releases energy by losing a phosphate group.
NAD+ / NADH
[ /næd / nˈæd/ ]
烟酰胺腺嘌呤二核苷酸
📖 定义
Nicotinamide adenine dinucleotide; a coenzyme that functions as an electron carrier, alternating between its oxidized (NAD+) and reduced (NADH) states during metabolism.
cellular respiration
[ /ˈsɛljələr ˌrɛspərˈeɪʃən/ ]
细胞呼吸
📖 定义
A process that converts glucose into ATP by breaking down organic molecules in the presence of oxygen.
electron carrier
[ /ˌɪˈlɛktrɑn ˈkɛriər/ ]
电子载体
📖 定义
A molecule, such as NADH or FADH2, that transports high-energy electrons during cellular respiration or photosynthesis.
FAD / FADH2
[ /fæd / fˈæd/ ]
黄素腺嘌呤二核苷酸
📖 定义
Flavin adenine dinucleotide; a redox-active electron carrier that accepts two electrons and two protons to form FADH2 during the citric acid cycle.
glycolysis
[ /ɡlaɪˈkɑːləsɪs/ ]
糖酵解
📖 定义
The first step of cellular respiration, where glucose is broken down into pyruvate， yielding ATP and NADH.
pyruvate / pyruvic acid
[ /paɪˈruːveɪt / pɪrˈuːvɪk ˈæsəd/ ]
丙酮酸
📖 定义
A three-carbon organic acid that is the end product of glycolysis and the starting substrate for the link reaction (pyruvate oxidation) in aerobic respiration or fermentation.
pyruvate oxidation
[ /paɪˈruːveɪt ˌɑksəˈdeɪʃən/ ]
丙酮酸氧化
📖 定义
The process of converting pyruvate into acetyl-CoA, producing NADH and releasing carbon dioxide.
coenzyme A
[ /koʊˈɛnzaɪm ə/ ]
辅酶A
📖 定义
A vital sulfur-containing coenzyme derived from pantothenic acid (vitamin B5) that accepts acetyl groups from pyruvate to form acetyl-CoA, fueling the citric acid cycle.
acetyl-CoA
[ /əsˌiːktoʊlˈiːkə/ ]
乙酰辅酶A
📖 定义
The two-carbon acetyl group attached to coenzyme A; forms when pyruvate is oxidized and enters the citric acid cycle by combining with oxaloacetate.
Krebs cycle
[ /krɛbz ˈsaɪkəl/ ]
三羧酸循环 (克雷布斯循环)
📖 定义
A series of enzymatic reactions that produce ATP, NADH, and FADH2 by oxidizing acetyl-CoA
oxidative phosphorylation
[ /ˈɑːksədˌeɪtɪv fˌoʊsfərˈeɪʃənliː/ ]
氧化磷酸化
📖 定义
The production of ATP using energy derived from the electron transport chain and chemiosmosis.
citric acid cycle
[ /ˈsɪtrɪk ˈæsəd ˈsaɪkəl/ ]
柠檬酸循环
📖 定义
A cyclic metabolic pathway of eight chemical reactions in the mitochondrial matrix that oxidizes acetyl-CoA into carbon dioxide, generating ATP/GTP, NADH, and FADH2.
electron transport chain (ETC)
[ /ˌɪˈlɛktrɑn ˈtrænspɔrt ʧeɪn/ ]
电子传递链
📖 定义
A series of protein complexes that transfer electrons, creating a proton gradient used for ATP synthesis.
chemiosmosis
[ /ˌkɛmiɑːzˈmoʊsɪs/ ]
化学渗透
📖 定义
The movement of protons across a membrane to drive ATP synthesis using ATP synthase.
ATP synthase
[ /ˌeɪ.tiːˈpiː ˈsɪnθeɪs/ ]
ATP合成酶
📖 定义
An enzyme that synthesizes ATP by using the energy from a proton gradient across a membrane.
fermentation
[ /ˌfərmənˈteɪʃən/ ]
发酵
📖 定义
An anaerobic process that generates ATP by converting glucose into byproducts like ethanol or lactic acid.
alcohol fermentation
[ /ˈælkəˌhɑl ˌfərmənˈteɪʃən/ ]
酒精发酵
📖 定义
A type of fermentation where glucose is converted into ethanol, carbon dioxide， and ATP.
ethanol
[ /ˈɛθəˌnɔl/ ]
乙醇 / 酒精
📖 定义
A two-carbon alcohol (C2H5OH) produced from pyruvate by yeasts and bacteria during anaerobic alcohol fermentation, regenerating NAD+ from NADH.
lactic acid fermentation
[ /ˈlæktɪk ˈæsəd ˌfərmənˈteɪʃən/ ]
乳酸发酵
📖 定义
A type of fermentation where glucose is converted into lactic acid and ATP.
photosynthesis
[ /ˌfoʊtoʊˈsɪnθəsɪs/ ]
光合作用
📖 定义
The process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose.
stoma / stomata
[ /ˈstoʊmə / ˈstoʊmətə/ ]
气孔
📖 定义
Microscopic openings on plant leaf surfaces regulated by guard cells that permit exchange of carbon dioxide and oxygen and regulate water vapor loss.
light-dependent reaction (light reaction)
[ /lˈaɪtədˌɛnpənt riˈækʃən/ ]
光反应
📖 定义
The first stage of photosynthesis, where light energy is captured to produce ATP and NADPH.
chlorophyll
[ /ˈklɔːrəfɪl/ ]
叶绿素
📖 定义
A green photosynthetic pigment embedded in thylakoid membranes that absorbs blue and red wavelengths of light while reflecting green light.
photosystem I (PSI)
[ /ˈfoʊtoʊˌsɪstəm aɪ/ ]
光系统I
📖 定义
A light-harvesting protein-pigment complex in the thylakoid membrane with a reaction-center chlorophyll a pair known as P700; transfers electrons to NADP+ reductase.
photosystem II (PSII)
[ /ˈfoʊtoʊˌsɪstəm ˈiː/ ]
光系统II
📖 定义
The light-harvesting complex in thylakoid membranes with P680 chlorophyll a that absorbs photons, splits water (photolysis), and releases O2 to initiate electron transport.
light-independent reaction (dark reaction)
[ /lˈaɪtɪndɪpəntənd riˈækʃən/ ]
暗反应
📖 定义
The enzymatic reactions of photosynthesis (Calvin cycle) occurring in the stroma of chloroplasts that fix atmospheric CO2 into carbohydrate using ATP and NADPH generated by the light reactions.
Calvin cycle
[ /ˈkælvɪn ˈsaɪkəl/ ]
卡尔文循环
📖 定义
The second stage of photosynthesis, where ATP and NADPH are used to convert carbon dioxide into glucose.
glyceraldehyde 3-phosphate (G3P)
[ /ɡlˈaɪsərˌeɪldˌeɪ -ˈfɑsfeɪt/ ]
甘油醛-3-磷酸
📖 定义
A three-carbon carbohydrate that is the direct product of the Calvin cycle and a pivotal metabolic intermediate in glycolysis and glucose synthesis.
carbon fixation
[ /ˈkɑrbən fɪkˈseɪʃən/ ]
固碳作用
📖 定义
The initial incorporation of inorganic carbon from CO2 into an organic compound (such as RuBP by the enzyme Rubisco) during the first phase of the Calvin cycle.
signal transduction
[ /ˈsɪgnəl trænzdˈʌkʃən/ ]
信号传导
📖 定义
The process by which a cell converts an external signal into a functional response.
signaling molecule
[ /ˈsɪgnəlɪŋ ˈmɑləˌkjul/ ]
信号分子
📖 定义
A chemical that conveys information between cells, such as hormones or neurotransmitters.
ligand
[ /ˈlɪgənd/ ]
配体
📖 定义
A molecule that binds specifically to a receptor to trigger a cellular response.
ligand-binding domain
[ /lˈaɪɡəndˌaɪnd doʊˈmeɪn/ ]
配体结合结构域
📖 定义
The specific region or pocket on a receptor protein where a signaling molecule (ligand) binds with high structural and chemical specificity to trigger receptor activation.
receptor
[ /riˈsɛptər/ ]
受体
📖 定义
A protein that detects signaling molecules and initiates a cellular response.
membrane-bound receptor
[ /mˌɛmbrəndˈænb riˈsɛptər/ ]
膜结合受体
📖 定义
A receptor embedded in the cell membrane that interacts with extracellular ligands.
membrane-binding domain
[ /mˈɛmbrəndˌaɪnɪŋ doʊˈmeɪn/ ]
膜结合结构域
📖 定义
A specialized structural region of an intracellular protein that recognizes and binds specific lipid headgroups or transmembrane receptor tails.
intracellular / cytoplasmic domain
[ /ɪntrˈɛsəljər / ˌsaɪtəˈplæzmɪk doʊˈmeɪn/ ]
细胞内结构域
📖 定义
The region of a transmembrane receptor located on the cytoplasmic interior of the cell that transmits the external signal into downstream intracellular cascades upon ligand binding.
G protein-coupled receptor (GPCR)
[ /ʤi prətˈɛŋkətəld riˈsɛptər/ ]
G蛋白偶联受体
📖 定义
A membrane receptor that activates G proteins when a ligand binds to it.
ligand-gated channel
[ /lˈɪɡəntˌeɪdʒd ˈʧænəl/ ]
配体门控通道蛋白
📖 定义
A protein chanel that opens or closes in response to the binding of a ligand， allowing ions to pass.
cyclic AMP (cAMP)
[ /ˈsaɪklɪk æmp/ ]
环腺苷酸 (cAMP)
📖 定义
Cyclic adenosine monophosphate; a key second messenger produced from ATP by adenylyl cyclase that activates protein kinase A (PKA) in cell signaling cascades.
second messenger
[ /ˈsɛkənd ˈmɛsɪnʤər/ ]
第二信使
📖 定义
A small molecule, such as cAMP or calcium, that relays a signal inside a cell after receptor activation.
phosphorylation cascade
[ /fˌoʊsfərˈeɪʃənliː kæˈskeɪd/ ]
磷酸化级联反应
📖 定义
A series of protein phosphorylation events that amplify and propagate a cellular signal.
phosphorylation
[ /fˌoʊsfərˈeɪʃənliː/ ]
磷酸化
📖 定义
The enzymatic covalent attachment of a phosphate group (PO4^3-) to a molecule (such as a protein by a kinase or ADP to make ATP), often altering protein activity, conformation, or localization.
kinase
[ /kˈɪnəs/ ]
蛋白激酶
📖 定义
An enzyme that catalyzes the transfer of a phosphate group to a substrate.
intracellular receptor
[ /ɪntrˈɛsəljər riˈsɛptər/ ]
细胞内受体
📖 定义
A receptor located within the cell that binds to small or hydrophobic signaling molecules.
feedback
[ /ˈfidˌbæk/ ]
反馈调节
📖 定义
A regulatory mechanism in which the output of a process influences its own activity.
negative feedback
[ /ˈnɛgətɪv ˈfidˌbæk/ ]
负反馈
📖 定义
A mechanism that reduces the output of a process to maintain homeostasis.
mitosis
[ /maɪˈtoʊsɪs/ ]
有丝分裂
📖 定义
A process of nuclear division in which a single cell divides to produce two identical daughter cells.
homeostasis
[ /ˌhoʊmioʊˈsteɪsɪs/ ]
内稳态 / 动态平衡
📖 定义
The maintenance of a stable internal environment despite exteral changes.
positive feedback
[ /ˈpɑzətɪv ˈfidˌbæk/ ]
正反馈
📖 定义
A mechanism that amplifies the output of a process, driving it further in the same direction.
parent cell (parental cell)
[ /ˈpɛrənt sɛl/ ]
母细胞
📖 定义
The original cell that undergoes replication of its genetic material and division (by mitosis or meiosis) to produce daughter cells.
daughter cell
[ /ˈdɔtər sɛl/ ]
子细胞
📖 定义
A cell formed by the division of a parental cell; genetically identical following mitosis, or genetically unique and haploid following meiosis.
asexual reproduction
[ /eɪˈsɛksjuəl ˌriprəˈdəkʃən/ ]
无性生殖
📖 定义
The production of offspring without the involvement of gametes or genetic recombination.
cell cycle
[ /sɛl ˈsaɪkəl/ ]
细胞周期
📖 定义
The sequence of events in the life of a cell, including growth, DNA replication, and division.
interphase
[ /ˈɪntərfˌeɪs/ ]
分裂间期
📖 定义
The preparatory period in the eukaryotic cell cycle between successive mitotic divisions, encompassing G1, S, and G2 phases, where cell growth and DNA replication occur.
mitotic phase (M phase)
[ /ˌmaɪˈtɔtɪk feɪz/ ]
分裂期 (M期)
📖 定义
The phase of the cell cycle that includes mitosis (nuclear division) and cytokinesis (cytoplasmic division), partitioning replicated chromosomes into two daughter cells.
G1 phase (G1 stage)
[ /ˈdʒiː ˈwʌn feɪz/ ]
G1期 (DNA合成前期)
📖 定义
The first gap phase of interphase in the cell cycle prior to DNA synthesis, characterized by intense cellular growth, protein synthesis, and organelle replication.
G2 phase (G2 stage)
[ /ˈdʒiː ˈtuː feɪz/ ]
G2期 (DNA合成后期)
📖 定义
The second gap phase of interphase following DNA replication, during which the cell completes preparation and synthesizes proteins required for mitosis.
S phase (S stage)
[ /ˈɛs feɪz/ ]
S期 (DNA合成期)
📖 定义
The synthesis subphase of interphase in the cell cycle during which genomic DNA is replicated and centrosomes duplicate in preparation for cell division.
chromatid
[ /ˈkroʊmətɪd/ ]
染色单体
📖 定义
One of the two identical copies of DNA in a duplicated chromosome.
chromosome
[ /ˈkroʊməˌzoʊm/ ]
染色体
📖 定义
A structure made of DNA and proteins in a compact form that carries genetic information in cells.
chromatin
[ /ˈkroʊmətɪn/ ]
染色质
📖 定义
The complex of DNA and proteins in a loose form that forms chromosomes within the nucleus.
sister chromatid
[ /ˈsɪstər ˈkroʊmətɪd/ ]
姐妹染色单体
📖 定义
Two identical chromatids connected at a centromere, resulting from DNA replication.
centromere
[ /ˈsɛntrəmiːr/ ]
着丝粒
📖 定义
The constricted, specialized DNA region of a duplicated chromosome where sister chromatids are held closest together and where the kinetochore forms.
prophase
[ /prˈɑːfəs/ ]
前期
📖 定义
The first stage of mitosis, during which chromatin condenses into visible chromosomes, nucleoli disappear, and the mitotic spindle begins to assemble.
metaphase
[ /mˈɛtəfˌeɪz/ ]
中期
📖 定义
The stage of mitosis in which all duplicated chromosomes are aligned along the spindle equator (metaphase plate) midway between spindle poles.
anaphase
[ /ˈænəfˌeɪz/ ]
后期
📖 定义
The stage of mitosis in which sister chromatids separate at their centromeres and are pulled by kinetochore microtubules toward opposite spindle poles.
telophase
[ /tˈɛləfˌeɪz/ ]
末期
📖 定义
The final stage of mitosis in which daughter nuclei form at the poles, nuclear envelopes reassemble, nucleoli reappear, and chromosomes begin to decondense.
spindle fiber (microtubule)
[ /ˈspɪndəl ˈfaɪbər/ ]
纺锤丝 / 纺锤体微管
📖 定义
Microtubule polymers that extend from the centrosomes to attach to kinetochores or interdigitate at the spindle equator, orchestrating chromosome movement during mitosis and meiosis.
kinetochore
[ /kɪˈnɛtəkɔːr/ ]
动粒 / 着丝点
📖 定义
A specialized disc-shaped multiprotein structure attached to the centromere of each sister chromatid that links chromatids to mitotic spindle microtubules.
metaphase plate
[ /mˈɛtəfˌeɪz pleɪt/ ]
中期板
📖 定义
An imaginary plane perpendicular to the spindle axis halfway between the two poles of a dividing cell along which chromosomes align during metaphase.
equatorial plate (equator)
[ /ˌikwəˈtɔriəl pleɪt/ ]
赤道板
📖 定义
An imaginary plane perpendicular to the spindle axis halfway between the two spindle poles where duplicated chromosomes align during metaphase.
cytokinesis
[ /sˌaɪtəkˈiːnsənz/ ]
胞质分裂
📖 定义
The division of the cytoplasm to form two separate daughter cells after mitosis.
cell plate
[ /sɛl pleɪt/ ]
细胞板
📖 定义
A structure that forms in plant cells during cytokinesis to divide the cell into two.
cyclin-dependent kinase (CDK)
[ /sˈaɪkəldˌɪnspˌɛnt kˈɪnəs/ ]
周期蛋白依赖性激酶
📖 定义
An enzyme that drives cell cycle progression when activated by cyclins.
cyclin
[ /sˈɪklɪn/ ]
细胞周期蛋白
📖 定义
A protein that regulates the cell cycle by activating cyclin-dependent kinases （CDKs）.
checkpoint
[ /ˈʧɛkˌpɔɪnt/ ]
细胞周期检查点
📖 定义
A control point in the cell cycle where progression is halted until conditions are met.
G1 checkpoint
[ /ʤi ˈʧɛkˌpɔɪnt/ ]
G1检查点
📖 定义
The primary control point (restriction point) in the cell cycle at the G1/S transition that assesses cell size, nutrient availability, growth factor signals, and DNA integrity before committing to replication.
G2 checkpoint
[ /ʤi ˈʧɛkˌpɔɪnt/ ]
G2检查点
📖 定义
The regulatory checkpoint occurring at the G2/M transition that verifies successful and complete DNA replication and checks for DNA damage before permitting mitotic division.
M checkpoint
[ /ɛm ˈʧɛkˌpɔɪnt/ ]
M检查点
📖 定义
The spindle assembly checkpoint (SAC) during metaphase that ensures all sister chromatids are correctly attached to spindle microtubules via kinetochores before initiating anaphase.
G0 phase (G0 stage)
[ /ˈdʒiː ˈzɪroʊ feɪz/ ]
G0期 (休眠期/静止期)
📖 定义
A non-dividing, quiescent state in which cells exit the cell cycle and perform differentiated physiological functions; can be temporary or permanent.
cancer
[ /ˈkænsər/ ]
癌症 / 恶性肿瘤
📖 定义
A disease characterized by uncontrolled cell division due to failures in cell cycle regulation.
haploid (n)
[ /ˈhæplɔɪd/ ]
单倍体
📖 定义
A cell containing one complete set of chromosomes, typical of gametes.
diploid (2n)
[ /ˈdɪplɔɪd/ ]
二倍体
📖 定义
A cell containing two complete sets of chromosomes, one from each parent.
homologous chromosome
[ /hɑˈmɑləgəs ˈkroʊməˌzoʊm/ ]
同源染色体
📖 定义
A pair of chromosomes, one from each parent, that are similar in shape, size, and gene content.
autosome
[ /ˈɔːtoʊsˌoʊm/ ]
常染色体
📖 定义
Any chromosome that is not a sex chromosome.
sex chromosome
[ /sɛks ˈkroʊməˌzoʊm/ ]
性染色体
📖 定义
A chromosome involved in determining the sex of an organism, such as X and Y in humans.
sexual reproduction
[ /ˈsɛkʃuəl ˌriprəˈdəkʃən/ ]
有性生殖
📖 定义
A mode of reproduction involving the fusion of gametes from two parents, resulting in offspring with genetic diversity.
gamete
[ /ˈɡæmiːt/ ]
配子
📖 定义
A mature haploid male or female reproductive cell (sperm or egg) capable of fusing with a gamete of the opposite sex during fertilization to form a diploid zygote.
sperm
[ /spərm/ ]
精子
📖 定义
The small, motile male gamete produced through spermatogenesis, delivering paternal genetic material to the ovum during fertilization.
egg
[ /ɛg/ ]
卵细胞 / 卵子
📖 定义
The non-motile, nutrient-dense female haploid gamete that fuses with a flagellated male sperm during fertilization to form a diploid zygote.
fertilization
[ /ˌfərtəlɪˈzeɪʃən/ ]
受精作用
📖 定义
The fusion of an egg and sperm cell to form a zygote.
zygote
[ /ˈzaɪɡoʊt/ ]
合子 / 受精卵
📖 定义
The diploid cell resulting from the fusion of male and female haploid gametes during fertilization, representing the initial cell of a new multicellular organism.
meiosis
[ /maɪˈoʊsɪs/ ]
减数分裂
📖 定义
A type of cell division that reduces chromosome number by half, producing haploid gametes.
meiosis I
[ /maɪˈoʊsɪs aɪ/ ]
减数第一次分裂
📖 定义
The first meiotic division (reduction division) in which homologous chromosome pairs synapse, undergo crossing over, and separate into two haploid daughter cells.
meiosis II
[ /maɪˈoʊsɪs ˈiː/ ]
减数第二次分裂
📖 定义
The second meiotic division (equational division) in which sister chromatids of duplicated haploid chromosomes separate, producing four genetically distinct haploid gametes.
crossing over
[ /ˈkrɔsɪŋ ˈoʊvər/ ]
交叉互换
📖 定义
The exchange of genetic material between homologous chromosomes during meiosis, increasing genetic diversity.
random assortment of chromosomes
[ /ˈrændəm əˈsɔrtmənt əv ˈkroʊməˌzoʊmz/ ]
染色体随机独立分配
📖 定义
The independent segregation of chromosomes during meiosis, contributing to genetic variation.
Mendelian genetics
[ /mɛndˈɛljən ʤəˈnɛtɪks/ ]
孟德尔遗传学
📖 定义
The fundamental principles of biological heredity formulated by Gregor Mendel, established by the law of segregation and the law of independent assortment of distinct particulate alleles.
genetic variation
[ /ʤəˈnɛtɪk ˌvɛriˈeɪʃən/ ]
遗传多样性 / 基因变异
📖 定义
Differences in DNA sequences among individuals within a population.
true-breeding
[ /trˈuːbrˌiːɪŋ/ ]
纯种 / 纯育品系
📖 定义
Referring to organisms that produce offspring of the same phenotypic variety when they self-pollinate or interbreed with another true-breeding organism of the same strain (homozygous).
cross / hybridization
[ /krɔs / ˌhaɪbrɪdaɪˈzeɪʃən/ ]
杂交
📖 定义
The controlled mating or breeding of two genetically distinct individuals to observe phenotypic ratios and inheritance patterns in offspring.
trait
[ /treɪt/ ]
性状
📖 定义
One of two or more detectable variants in an identifiable heritable phenotypic character (such as purple versus white flower color).
character
[ /ˈkɛrɪktər/ ]
特征
📖 定义
A heritable feature that varies among individuals in a population, such as flower color or eye color.
monohybrid cross
[ /mənˈɑːfɪbriːd krɔs/ ]
单因子杂交
📖 定义
A genetic cross between two individuals focusing on a single trait.
P generation (parental generation)
[ /pi ˌʤɛnərˈeɪʃən/ ]
亲代 (P代)
📖 定义
The true-breeding (homozygous) initial parental generation in a Mendelian breeding experiment whose offspring form the F1 generation.
F1 generation
[ /ɛf ˌʤɛnərˈeɪʃən/ ]
子一代 (F1代)
📖 定义
The first filial generation of hybrid offspring resulting from an experimental genetic cross between distinct parental (P generation) individuals.
F2 generation
[ /ɛf ˌʤɛnərˈeɪʃən/ ]
子二代 (F2代)
📖 定义
The second filial generation produced by interbreeding or self-pollination among individuals of the F1 generation.
Punnett square
[ /pˈʌnɪt skwɛr/ ]
棋盘格 / 庞氏表
📖 定义
A visual checkerboard diagram used in genetics to predict the genotype and phenotype ratios resulting from a particular cross.
complete dominance
[ /kəmˈplit ˈdɑmənəns/ ]
完全显性
📖 定义
A pattern of inheritance in which one allele completely masks the effect of another allele.
dominant
[ /ˈdɑmənənt/ ]
显性的
📖 定义
An allele that expresses its phenotype even in the presence of a different allele.
recessive
[ /rəˈsɛsɪv/ ]
隐性的
📖 定义
An allele whose phenotype is masked in the presence of a dominant allele.
monohybrid test cross
[ /mənˈɑːfɪbriːd tɛst krɔs/ ]
单因子测交
📖 定义
A cross between an individual showing the dominant phenotype (of unknown genotype) and a homozygous recessive individual for a single trait.
law of segregation
[ /lɔ əv ˌsɛgrəˈgeɪʃən/ ]
分离定律
📖 定义
Mendel's principle stating that two alleles for a trait separate during gamete formation.
phenotype
[ /ˈfiːnətaɪp/ ]
表型
📖 定义
The observable physical or physiological traits of an organism.
genotype
[ /ˈdʒiːnətaɪp/ ]
基因型
📖 定义
The genetic makeup of an organism, represented by its alleles.
homozygote / homozygous
[ /ˌhoʊmoʊˈzaɪgoʊt / ˌhoʊməˈzaɪɡəs/ ]
纯合子 / 纯合的
📖 定义
An individual with two identical alleles for a specific gene.
heterozygote / heterozygous
[ /hˌɛtərəsˈaɪtədʒ / ˌhɛtərəˈzaɪɡəs/ ]
杂合子 / 杂合的
📖 定义
An individual with two different alleles for a specific gene.
allele
[ /əˈliːl/ ]
等位基因
📖 定义
A variant form of a gene at a particular locus on a chromosome.
locus / loci
[ /ˈloʊkəs / ˈloʊki/ ]
基因座 / 位点
📖 定义
The specific physical location or position of a gene on a chromosome.
dihybrid cross
[ /dˈaɪəbrˌɪdə krɔs/ ]
双因子杂交
📖 定义
A genetic cross between two individuals focusing on two traits.
law of independent assortment
[ /lɔ əv ˌɪndɪˈpɛndənt əˈsɔrtmənt/ ]
自由组合定律
📖 定义
Mendel's principle stating that genes for different traits segregate independently during gamete formation.
dihybrid test cross
[ /dˈaɪəbrˌɪdə tɛst krɔs/ ]
双因子测交
📖 定义
A cross between an individual heterozygous for two distinct genes (AaBb) and a homozygous double recessive individual (aabb) to test for genetic linkage.
addition rule
[ /əˈdɪʃən rul/ ]
加法法则
📖 定义
A probability rule stating that the probability of occurrence of any one of two or more mutually exclusive events is calculated by adding their individual probabilities.
non-Mendelian genetics
[ /nˌɑːnmɛndˈɛliːən ʤəˈnɛtɪks/ ]
非孟德尔遗传
📖 定义
Inheritance patterns that depart from simple Mendelian dominant/recessive ratios, including codominance, incomplete dominance, multiple alleles, sex linkage, and polygenic traits.
multiplication rule
[ /ˌməltəpləˈkeɪʃən rul/ ]
乘法法则
📖 定义
A probability rule stating that the joint probability of two or more independent events occurring simultaneously is the product of their individual probabilities.
incomplete dominance
[ /ˌɪnkəmˈplit ˈdɑmənəns/ ]
不完全显性
📖 定义
A pattern of inheritance where the phenotype of heterozygotes is an intermediate blend of both alleles.
pleiotropy
[ /plaɪˈɑːtrəpi/ ]
一因多效 / 基因多效性
📖 定义
A single gene affecting multiple traits in an organism.
codominance
[ /koʊˈdɑːmɪnəns/ ]
共显性
📖 定义
A pattern of inheritance where both alleles in a heterozygote are fully expressed.
multiple alleles
[ /ˈməltəpəl əˈliːlz/ ]
复等位基因
📖 定义
More than two forms of a gene that can occupy a single locus.
non-nuclear inheritance
[ /ˈnɑˈnuˌkliər ˌɪnˈhɛrətəns/ ]
非核遗传 / 细胞质遗传
📖 定义
Inheritance of genetic material not found in the nucleus, such as mitochondrial DNA.
epistasis
[ /ɛˈpɪstəsɪs/ ]
上位效应 / 基因上位性
📖 定义
A genetic interaction where one gene masks or modifies the effect of another gene.
polygenic inheritance
[ /pˌɑːliːɡˈɛnɪk ˌɪnˈhɛrətəns/ ]
多基因遗传
📖 定义
An additive genetic effect of two or more independent genes determining a single phenotypic characteristic, resulting in continuous quantitative variation (e.g., human height and skin pigmentation).
sex-linked trait
[ /sˈɛkslˌaɪknd treɪt/ ]
伴性性状
📖 定义
A phenotypic trait determined by an allele situated on a sex chromosome (typically the X chromosome in humans), exhibiting characteristic sex-skewed inheritance frequencies.
sex-linked gene
[ /sˈɛkslˌaɪknd ʤin/ ]
伴性基因
📖 定义
A gene located on a sex chromosome, often showing different patterns of inheritance in males and females.
X chromosome
[ /ɛks ˈkroʊməˌzoʊm/ ]
X染色体
📖 定义
The larger of the two mammalian sex chromosomes; females carry two copies (XX) while males carry one copy (XY), encoding thousands of genes vital for both sexes.
Y chromosome
[ /waɪ ˈkroʊməˌzoʊm/ ]
Y染色体
📖 定义
The smaller mammalian sex chromosome that contains the SRY (sex-determining region Y) master gene responsible for triggering male testicular development in XY embryos.
linked genes
[ /lɪŋkt ʤinz/ ]
连锁基因
📖 定义
Genes located close together on the same chromosome that tend to be inherited together.
parental phenotype
[ /pərˈɛntəl ˈfiːnətaɪp/ ]
亲本表型
📖 定义
An offspring phenotype that precisely matches one of the original homozygous or heterozygous parental phenotypes involved in the cross, without recombination.
pedigree
[ /ˈpɛdəgri/ ]
系谱图 / 家族遗传系谱
📖 定义
A chart representing family relationships and inheritance patterns of traits.
recombinant phenotype
[ /rɪˈkɑmbɪnənt ˈfiːnətaɪp/ ]
重组表型
📖 定义
An offspring phenotype that exhibits a novel combination of traits differing from both parents, resulting from crossing over during meiosis or independent assortment.
linkage map
[ /ˈlɪŋkɪʤ mæp/ ]
连锁图谱 / 基因图谱
📖 定义
A genetic map depicting the relative locations of genes along a chromosome based on the frequency of meiotic crossing over (recombination frequency).
autosomal dominant trait
[ /ˌɔːtəsˈoʊməl ˈdɑmənənt treɪt/ ]
常染色体显性遗传性状
📖 定义
A phenotypic condition or trait caused by a dominant allele located on an autosome (non-sex chromosome), requiring only a single copy of the allele for phenotypic expression.
autosomal recessive trait
[ /ˌɔːtəsˈoʊməl rəˈsɛsɪv treɪt/ ]
常染色体隐性遗传性状
📖 定义
A phenotypic condition or trait caused by a recessive allele on an autosome, expressed exclusively in homozygous individuals who inherit mutant alleles from both parents.
X-linked dominant trait
[ /zˈɪlksɪnkəd ˈdɑmənənt treɪt/ ]
X连锁显性遗传性状
📖 定义
A mode of genetic inheritance where a dominant mutation on the X chromosome causes the phenotype; affected males transmit the condition to all daughters but no sons.
X-linked recessive trait
[ /zˈɪlksɪnkəd rəˈsɛsɪv treɪt/ ]
X连锁隐性遗传性状
📖 定义
A mode of inheritance caused by a recessive mutation on the X chromosome, expressing much more frequently in hemizygous males (XY) than in females (XX).
Y-linked trait
[ /jˈɪlŋktɪd treɪt/ ]
Y连锁遗传性状
📖 定义
A phenotypic trait determined exclusively by genes on the Y chromosome (holandric), transmitted strictly and directly from father to all biological sons.
maternal inheritance
[ /məˈtərnəl ˌɪnˈhɛrətəns/ ]
母系遗传
📖 定义
The transmission of genetic material exclusively from the mother, often via mitochondria.
carrier
[ /ˈkɛriər/ ]
致病基因携带者
📖 定义
An individual who has one copy of a recessive allele but does not exhibit the associated phenotype.
transformation experiment
[ /ˌtrænsfərˈmeɪʃən ɪkˈspɛrəmənt/ ]
转化实验
📖 定义
A landmark 1928 experiment by Frederick Griffith (and later refined in 1944 by Avery, MacLeod, and McCarty) demonstrating that genetic material can be transferred between bacterial cells, identifying DNA as the transforming principle.
transforming principle
[ /trænsˈfɔrmɪŋ ˈprɪnsəpəl/ ]
转化因子
📖 定义
The early biochemical term for the substance (identified by Avery, MacLeod, and McCarty as DNA) responsible for transferring genetic information between bacterial strains in Griffith's experiment.
bacteriophage / phage
[ /bæktˌɪrjˈuːdʒˌæf / feɪʤ/ ]
噬菌体
📖 定义
A virus that infects and replicates within bacteria.
semiconservative model
[ /sˌɛmiːkənsərpˈæʃɪv ˈmɑdəl/ ]
半保留复制模型
📖 定义
A model of DNA replication in which each new DNA molecule consists of one original strand and one newly synthesized strand.
template strand / parental strand
[ /ˈtɛmplət strænd / pərˈɛntəl strænd/ ]
模板链 / 母链
📖 定义
The specific strand of a double-stranded DNA molecule that serves as the guide for the synthesis of a complementary RNA during transcription or a new DNA strand during replication.
DNA replication
[ /ˌdiː.ɛnˈeɪ ˌrɛplɪˈkeɪʃən/ ]
DNA复制
📖 定义
The process of copying a DNA molecule to produce two identical DNA strands.
new strand / daughter strand
[ /nu strænd / ˈdɔtər strænd/ ]
新合成链 / 子链
📖 定义
The newly synthesized complementary DNA strand formed during replication through phosphodiester bond synthesis catalyzed by DNA polymerase.
origin of replication
[ /ˈɔrəʤən əv ˌrɛplɪˈkeɪʃən/ ]
复制起始点
📖 定义
A specific nucleotide sequence along a chromosome where DNA replication begins and replication bubbles open.
replication fork
[ /ˌrɛplɪˈkeɪʃən fɔrk/ ]
复制叉
📖 定义
A Y-shaped region on a replicating DNA molecule where the parental double helix is unwound and new strands are continuously and discontinuously synthesized.
helicase
[ /ˈhɛlɪkeɪs/ ]
解旋酶
📖 定义
An enzyme that unwinds the DNA double helix by breaking hydrogen bonds between complementary bases.
topoisomerase
[ /təpˈɔɪzmˌɑːrəs/ ]
拓扑异构酶
📖 定义
An enzyme that prevents the overwinding or tangling of DNA during replication by cutting and rejoining DNA strands.
primase
[ /priːmˈɑːsiː/ ]
引物酶
📖 定义
An RNA polymerase enzyme that synthesizes short RNA primers (approx. 5-10 nucleotides) providing a 3'-OH group required for DNA polymerase initiation.
primer
[ /ˈpraɪmər/ ]
RNA引物
📖 定义
A short RNA sequence that provides a starting point for DNA synthesis.
DNA polymerase
[ /ˌdiː.ɛnˈeɪ pəˈlɪməreɪs/ ]
DNA聚合酶
📖 定义
An enzyme that synthesizes new DNA strands by adding nucleotides to a template strand
leading strand
[ /ˈlidɪŋ strænd/ ]
前导链
📖 定义
The DNA strand synthesized continuously in the 5' to 3' direction during replication.
DNA ligase
[ /ˌdiː.ɛnˈeɪ ˈlaɪɡeɪs/ ]
DNA连接酶
📖 定义
An enzyme that joins DNA fragments by forming phosphodiester bonds.
lagging strand
[ /ˈlægɪŋ strænd/ ]
后随链 / 滞后链
📖 定义
The DNA strand synthesized discontinuously in short fragments, called Okazaki fragments, during replication.
Okazaki fragment
[ /ˌoʊkəˈzɑːki ˈfræɡmənt/ ]
冈崎片段
📖 定义
A series of short, discontinuously synthesized DNA segments on the lagging strand during DNA replication, subsequently joined by DNA ligase.
naked DNA
[ /ˈneɪkəd ˈdiˌɛˈneɪ/ ]
裸露DNA (无组蛋白包裹)
📖 定义
DNA that is not packaged or wrapped around histone protein octamers, characteristic of prokaryotic nucleoids, circular bacterial plasmids, chloroplasts, and mitochondria.
histone
[ /hˈɪstoʊn/ ]
组蛋白
📖 定义
A small, highly basic protein rich in lysine and arginine that binds electrostatically to negatively charged DNA, assembling into octamers around which DNA winds to form nucleosomes.
plasmid
[ /ˈplæzmɪd/ ]
质粒
📖 定义
A small, circular piece of DNA found in bacteria, often used in genetic engineering.
gene
[ /ʤin/ ]
基因
📖 定义
A segment of DNA that encodes a functional product, usually a protein.
gene expression
[ /ʤin ɪkˈsprɛʃən/ ]
基因表达
📖 定义
The process by which information from a gene is used to synthesize RNA and proteins.
central dogma
[ /ˈsɛntrəl ˈdɑgmə/ ]
中心法则
📖 定义
The concept that genetic information flows from DNA to RNA to protein.
transcription
[ /ˌtrænˈskrɪpʃən/ ]
转录
📖 定义
The process of synthesizing RNA from a DNA template.
translation
[ /trænzˈleɪʃən/ ]
翻译
📖 定义
The process of synthesizing a protein from an mRNA template.
promoter
[ /prəˈmoʊtər/ ]
启动子
📖 定义
A DNA sequence that signals the start of transcription and is recognized by RNA polymerase.
RNA polymerase
[ /ˌɑːr.ɛnˈeɪ pəˈlɪməreɪs/ ]
RNA聚合酶
📖 定义
An enzyme that synthesizes RNA by using a DNA template.
transcription factor
[ /ˌtrænˈskrɪpʃən ˈfæktər/ ]
转录因子
📖 定义
A protein that binds to DNA and regulates the transcription of genes.
non-template strand
[ /nˈɔːntmpˌɔːltˌeɪ strænd/ ]
非模板链
📖 定义
The strand of DNA that is not transcribed into RNA; possesses the identical base sequence to the resulting mRNA transcript (with T instead of U), also called coding strand.
coding strand
[ /ˈkoʊdɪŋ strænd/ ]
编码链
📖 定义
The DNA strand whose base sequence corresponds directly to the codon sequence of the mRNA transcript produced (with thymine in place of uracil).
template strand
[ /ˈtɛmplət strænd/ ]
模板链
📖 定义
The specific strand of a double-stranded DNA molecule that serves as the guide for the synthesis of a complementary RNA during transcription or a new DNA strand during replication.
non-coding strand
[ /nˈɑːndˈoʊkɪŋ strænd/ ]
非编码链
📖 定义
Alternative term for the template strand of DNA; serves as the template read by RNA polymerase in the 3' to 5' direction during transcription.
messenger RNA (mRNA)
[ /ˈmɛsɪndʒər ˌɑːr.ɛnˈeɪ/ ]
信使RNA
📖 定义
RNA that carries genetic information from DNA to ribosomes for protein synthesis.
pre-mRNA
[ /prˈɛmnrə/ ]
前体信使RNA
📖 定义
The initial RNA transcript produced during transcription, which requires processing before becoming mature mRNA
RNA processing
[ /rˈeɪn ˈprɑsɛsɪŋ/ ]
RNA加工 / 转录后加工
📖 定义
The modification of pre-mRNA, including splicing, capping, and adding a poly-A tail, to produce mature mRNA.
5' cap (GTP cap)
[ /kæp/ ]
5'端帽子 (GTP帽子)
📖 定义
A specially altered guanine nucleotide (7-methylguanosine) added to the 5' end of eukaryotic pre-mRNA to prevent nucleolytic degradation and assist ribosome binding.
poly-A tail
[ /pˈoʊliːə teɪl/ ]
多聚腺苷酸尾 (poly-A尾)
📖 定义
A stretch of 50 to 250 adenine nucleotides added enzymatically to the 3' end of pre-mRNA during eukaryotic mRNA processing to enhance stability and nuclear export.
RNA splicing
[ /rˈeɪn ˈsplaɪsɪŋ/ ]
RNA剪接
📖 定义
The removal of introns and joining of exons in pre-mRNA to form mature mRNA
alternative RNA splicing
[ /ɔlˈtərnətɪv rˈeɪn ˈsplaɪsɪŋ/ ]
选择性剪接
📖 定义
A process that allows a single gene to produce multiple protein variants by splicing pre-mRNA in different ways.
intron
[ /ˈɪntrɑːn/ ]
内含子
📖 定义
A non-coding sequence of RNA that is removed during RNA splicing.
exon
[ /ˈɛksɑːn/ ]
外显子
📖 定义
A coding sequence of RNA that remains in mature mRNA after splicing
genetic code
[ /ʤəˈnɛtɪk koʊd/ ]
遗传密码
📖 定义
The set of rules by which nucleotide sequences in mRNA are translated into amino acids.
start codon
[ /stɑrt kˈoʊdən/ ]
起始密码子
📖 定义
The specific mRNA codon (typically 5'-AUG-3') that signals the ribosome to begin translation and codes for the first amino acid, methionine.
codon
[ /kˈoʊdən/ ]
密码子
📖 定义
A three-nucleotide sequence in mRNA that specifies a particular amino acid or stop signal during translation.
stop codon
[ /stɑp kˈoʊdən/ ]
终止密码子
📖 定义
One of three specific mRNA triplet codons (5'-UAA-3', 5'-UAG-3', 5'-UGA-3') that do not code for amino acids and signal the release factor to terminate translation.
transfer RNA (tRNA)
[ /ˈtrænsfɜːr ˌɑːr.ɛnˈeɪ/ ]
转运RNA
📖 定义
RNA that carries amino acids to ribosomes and matches them to codons in mRNA during translation.
anticodon
[ /ˌæntiːkˈɑːdən/ ]
反密码子
📖 定义
A three-nucleotide sequence in tRNA that pairs with a complementary codon in mRNA.
virus
[ /ˈvaɪrəs/ ]
病毒
📖 定义
A small infectious agent composed of genetic material and a protein coat, capable of replicating only inside a host cell.
DNA virus
[ /ˈdiˌɛˈneɪ ˈvaɪrəs/ ]
DNA病毒
📖 定义
A virus whose genetic genome consists of either single-stranded or double-stranded DNA, replicating via DNA-dependent DNA polymerases within host cells.
RNA virus
[ /rˈeɪn ˈvaɪrəs/ ]
RNA病毒
📖 定义
A virus whose genome consists of RNA (positive-sense, negative-sense, or retroviral), replicating using RNA-dependent RNA polymerases or reverse transcriptase.
capsid
[ /kˈæpst/ ]
衣壳 / 病毒蛋白质外壳
📖 定义
The protective external protein shell of a virus that encloses and shields its viral genetic material (DNA or RNA) from degradation.
retrovirus
[ /ˌrɛtroʊˈvaɪrəs/ ]
逆转录病毒
📖 定义
A virus that uses reverse transcription to convert its RNA genome into DNA.
reverse transcription
[ /rɪˈvərs ˌtrænˈskrɪpʃən/ ]
逆转录
📖 定义
The process of synthesizing DNA from an RNA template.
gene regulation
[ /ʤin ˌrɛgjəˈleɪʃən/ ]
基因表达调控
📖 定义
The control of gene expression, ensuring that genes are expressed at the right times and levels.
regulatory sequence
[ /ˈrɛgjələˌtɔri ˈsikwəns/ ]
调控序列
📖 定义
A DNA sequence that influences gene expression by serving as a binding site for regulatory proteins.
reverse transcriptase
[ /rɪˈvərs trænskrˈɪpstˌeɪts/ ]
逆转录酶
📖 定义
An enzyme used by retroviruses to carry out reverse transcription.
trp operon
[ /trˈɛptər ˈɑːpərɑːn/ ]
色氨酸操纵子
📖 定义
A repressible bacterial operon in E. coli containing genes for tryptophan biosynthesis, repressed when tryptophan levels are high and binds to the Trp repressor.
differentiation
[ /ˌdɪfərˌɛnʧiˈeɪʃən/ ]
细胞分化
📖 定义
The biological developmental process by which unspecialized stem cells become structurally and functionally specialized through selective differential gene expression.
operon
[ /ˈɑːpərɑːn/ ]
操纵子
📖 定义
A cluster of genes under the control of a single promoter, typically found in prokaryotes.
lac operon
[ /læk ˈɑːpərɑːn/ ]
乳糖操纵子
📖 定义
An inducible bacterial operon in E. coli that encodes enzymes for lactose uptake and catabolism, activated in the presence of lactose (allolactose) and absence of glucose.
operator
[ /ˈɑpərˌeɪtər/ ]
操纵基因 / 操纵序列
📖 定义
A regulatory DNA sequence in a prokaryotic operon located within or near the promoter where an active repressor protein binds to block RNA polymerase transcription.
regulatory gene
[ /ˈrɛgjələˌtɔri ʤin/ ]
调控基因
📖 定义
A gene that codes for a protein (such as a repressor, activator, or transcription factor) that controls the transcription of other target genes or operons.
histone acetylation
[ /hˈɪstoʊn ˌeɪsətəlˈeɪʃən/ ]
组蛋白乙酰化
📖 定义
The addition of acetyl groups to histones, loosening chromatin structure and promoting gene expression.
DNA methylation
[ /ˈdiˌɛˈneɪ mˌɛθliːˈeɪtənəl/ ]
DNA甲基化
📖 定义
The addition of methyl groups to DNA, typically suppressing gene expression.
repressor
[ /rɪprˈɛsər/ ]
阻遏蛋白
📖 定义
A protein that inhibits transcription by binding to a regulatory sequence.
general transcription factor
[ /ˈʤɛnərəl ˌtrænˈskrɪpʃən ˈfæktər/ ]
通用转录因子
📖 定义
An essential regulatory protein that binds directly to the promoter (such as the TATA box) or to RNA polymerase II, assembling the basal transcription pre-initiation complex.
specific transcription factor
[ /spɪˈsɪfɪk ˌtrænˈskrɪpʃən ˈfæktər/ ]
特异性转录因子
📖 定义
A regulatory protein (activator or repressor) that binds to distal enhancers or proximal elements to dramatically modulate the rate of transcription of specific target genes.
enhancer
[ /ɛnˈhænsər/ ]
增强子
📖 定义
A DNA sequence that increases the transcription of a gene when bound by activators.
activator
[ /ˈæktəˌveɪtər/ ]
激活蛋白 / 活化剂
📖 定义
A protein that increases gene expression by binding to regulatory sequences.
mutation
[ /mjuˈteɪʃən/ ]
基因突变
📖 定义
A change in the DNA sequence that can affect genetic information.
point mutation
[ /pɔɪnt mjuˈteɪʃən/ ]
点突变
📖 定义
A single nucleotide change in a DNA sequence.
silent mutation
[ /ˈsaɪlənt mjuˈteɪʃən/ ]
同义突变 / 沉默突变
📖 定义
A mutation that does not alter the amino acid sequence of a protein.
substitution mutation
[ /ˌsəbstɪˈtuʃən mjuˈteɪʃən/ ]
碱基替换突变
📖 定义
A type of point mutation where one nucleotide base pair in DNA is replaced by another, which can result in silent, missense, or nonsense codons.
missense mutation
[ /mɪsˈɛns mjuˈteɪʃən/ ]
错义突变
📖 定义
A mutation that results in a different amino acid being incorporated into a protein.
nonsense mutation
[ /ˈnɑnsɛns mjuˈteɪʃən/ ]
无义突变
📖 定义
A mutation that introduces a premature stop codon, terminating protein synthesis.
insertion mutation
[ /ˌɪnˈsərʃən mjuˈteɪʃən/ ]
插入突变
📖 定义
A genetic mutation involving the addition of one or more nucleotide base pairs into a DNA sequence, frequently causing catastrophic reading frameshifts if not a multiple of three.
deletion mutation
[ /dɪˈliʃən mjuˈteɪʃən/ ]
缺失突变
📖 定义
A genetic mutation involving the loss or excision of one or more nucleotide base pairs from a DNA sequence, altering the protein sequence or shifting the reading frame.
frameshift mutation
[ /frˈeɪmʃˌɪft mjuˈteɪʃən/ ]
移码突变
📖 定义
A mutation caused by insertions or deletions that shift the reading frame of a gene.
sickle-cell anemia (sickle-cell disease)
[ /sˈɪksləs əˈnimiə/ ]
镰刀型细胞贫血症
📖 定义
A severe hereditary hemoglobinopathy caused by a point mutation (missense: GAG -> GTG, encoding Val instead of Glu at position 6 of the beta-globin chain), causing red blood cells to deform into sickled shapes.
duplication
[ /ˌdjupləˈkeɪʃən/ ]
重复突变 / 染色体重复
📖 定义
A chromosomal mutation or DNA sequence alteration in which an entire segment of genetic material is replicated, producing tandem redundant copies.
inversion
[ /ˌɪnˈvərʒən/ ]
倒位突变 / 染色体倒位
📖 定义
A chromosomal structural alteration in which a segment breaks off, reverses its orientation by 180 degrees, and reattaches to the same chromosome.
translocation
[ /trˌænzlɑːkˈeɪʃən/ ]
易位突变 / 染色体易位
📖 定义
A chromosomal mutation involving the breakage and attachment of a chromosome segment to an entirely non-homologous chromosome.
nondisjunction
[ /ˌnɑːndɪsˈdʒʌŋkʃən/ ]
染色体不分离
📖 定义
The failure of chromosomes to separate properly during cell division.
Down syndrome (Trisomy 21)
[ /daʊn ˈsɪndroʊm ˈtraɪsoʊmi ˈtwɛnti ˈwʌn/ ]
唐氏综合征 (21三体综合征)
📖 定义
A human chromosomal condition caused by the presence of an extra 21st chromosome (aneuploidy via nondisjunction), leading to developmental and intellectual variations.
polyploidy
[ /ˈpɑːliˌplɔɪdi/ ]
多倍体
📖 定义
A condition in which an organism has more than two complete sets of chromosomes.
triploidy
[ /trˈɪplˌɔɪd/ ]
三倍体
📖 定义
A chromosomal condition in which an organism possesses three complete sets of chromosomes (3n), resulting in reproductive sterility in animals.
tetraploidy
[ /tˌɛtrəpˈɑːldiː/ ]
四倍体
📖 定义
A polyploid condition in which an organism possesses four complete sets of chromosomes (4n), common in angiosperm plants and contributing to speciation.
spontaneous mutation
[ /spɑnˈteɪniəs mjuˈteɪʃən/ ]
自发突变
📖 定义
A genetic mutation that arises naturally inside cells from intrinsic biochemical errors during DNA replication, cellular oxidative stress, or spontaneous depurination/deamination.
induced mutation
[ /ˌɪnˈdust mjuˈteɪʃən/ ]
诱发突变
📖 定义
A genetic mutation produced deliberately or accidentally through exposure to external environmental mutagens, such as ionizing radiation, ultraviolet light, or reactive chemical mutagens.
horizontal gene transfer (lateral gene transfer)
[ /ˌhɔrəˈzɑntəl ʤin ˈtrænsfər/ ]
水平基因转移
📖 定义
The transmission of genetic material between distinct organisms across species or lineages without sexual reproduction, occurring via transformation, transduction, or conjugation.
mutagen
[ /mˈjutəʤɛn/ ]
诱变剂
📖 定义
An agent that induces genetic mutations.
transformation
[ /ˌtrænsfərˈmeɪʃən/ ]
转化作用
📖 定义
The uptake of foreign DNA by a cell from its surroundings.
transduction
[ /trænzdˈʌkʃən/ ]
转导作用
📖 定义
The transfer of genetic material between cells via a virus.
conjugation
[ /ˌkɑnʤəˈgeɪʃən/ ]
接合作用
📖 定义
The direct transfer of DNA between two bacterial cells through physical contact.
transposition
[ /trˌænspəzˈɪʃən/ ]
转座作用
📖 定义
The movement of DNA segments within a genome.
polymerase chain reaction (PCR)
[ /pəˈlɪməreɪs ʧeɪn riˈækʃən/ ]
聚合酶链式反应
📖 定义
A technique for amplifying DNA sequences in vitro.
viral reassortment
[ /ˈvaɪrəl rˌiːəsˈɜːrmənt/ ]
病毒基因重配
📖 定义
The exchange of genetic material between viruses infecting the same host, creating new viral strains.
biotechnology
[ /ˌbaɪoʊˌtɛkˈnɑləʤi/ ]
生物技术
📖 定义
The technological exploitation and manipulation of biological systems, living organisms, or genetic material to develop useful products and medical therapies.
denaturation
[ /dɪnˈækjətrˈeɪʃən/ ]
DNA变性 (解链)
📖 定义
A process in which a protein loses its native three-dimensional tertiary/secondary structure due to disruption of weak chemical bonds and interactions by heat, extreme pH, or chemical agents, rendering it biologically inactive.
annealing
[ /əˈnilɪŋ/ ]
引物退火 (复性)
📖 定义
The phase in PCR (polymerase chain reaction) where the reaction temperature is lowered to allow short oligonucleotide primers to hybridize to target DNA strands.
extension / elongation
[ /ɪkˈstɛnʃən / ˌilɔŋˈgeɪʃən/ ]
DNA延伸
📖 定义
The final stage of a PCR cycle in which Taq DNA polymerase synthesizes a complementary DNA strand by adding dNTPs to the 3' ends of primers at around 72°C.
gel electrophoresis
[ /ʤɛl ˌɪˌlɛktroʊfɔˈrɪsɪs/ ]
凝胶电泳
📖 定义
A method for separating DNA fragments based on size using an electric field.
DNA sequencing
[ /ˈdiˌɛˈneɪ ˈsikwənsɪŋ/ ]
DNA测序
📖 定义
The process of determining the nucleotide sequence of a DNA molecule.
genetic engineering
[ /ʤəˈnɛtɪk ˈɛnʤəˈnɪrɪŋ/ ]
基因工程
📖 定义
The direct manipulation of an organism's DNA to alter its characteristics.
restriction enzyme
[ /riˈstrɪkʃən ˈɛnˌzaɪm/ ]
限制性核酸内切酶
📖 定义
An enzyme that cuts DNA at specific sequences.
complementary DNA (cDNA)
[ /ˌkɑmpləˈmɛnʧi ˈdiˌɛˈneɪ/ ]
互补DNA
📖 定义
A DNA molecule synthesized from an RNA template using reverse transcriptase.
antibiotics
[ /ˌæntibaɪˈɑtɪks/ ]
抗生素
📖 定义
Substances that kill or inhibit the growth of bacteria.
antibiotic resistance gene
[ /ˌæntibaɪˈɑtɪk rɪˈzɪstəns ʤin/ ]
抗生素抗性基因
📖 定义
A gene (frequently carried on bacterial plasmids or transposons) that encodes proteins that neutralize, pump out, or destroy antibiotics, providing selective survival advantages.
evolution
[ /ˌɛvəˈluʃən/ ]
生物进化
📖 定义
The process by which populations of organisms change over generations through variations in their genetic composition.
natural selection
[ /ˈnæʧərəl səˈlɛkʃən/ ]
自然选择
📖 定义
The process where individuals with favorable traits are more likely to survive and reproduce, passing those traits to the next generation.
overproduction
[ /ˈoʊvərprəˈdəkʃən/ ]
过度繁殖
📖 定义
The evolutionary principle that organisms produce more offspring than the environment can support, creating intense competition for limited resources.
fitness
[ /ˈfɪtnəs/ ]
适应度 / 适应性
📖 定义
The ability of an organism to survive and reproduce in its environment.
adaptation
[ /ˌædəpˈteɪʃən/ ]
适应 / 适应特征
📖 定义
A heritable characteristic that improves an organism's ability to survive and reproduce in a specific environment.
sexual selection
[ /ˈsɛkʃuəl səˈlɛkʃən/ ]
性选择
📖 定义
A type of natural selection where individuals with certain traits are more likely to attract mates and reproduce.
artificial selection
[ /ˌɑrtəˈfɪʃəl səˈlɛkʃən/ ]
人工选择
📖 定义
The human-directed breeding of organisms to enhance desirable traits.
selective breeding
[ /səˈlɛktɪv ˈbridɪŋ/ ]
选择育种
📖 定义
The intentional, human-directed breeding of organisms with desirable phenotypic traits over generations to produce specialized varieties or breeds.
directional selection
[ /dɪˈrɛkʃɪnəl səˈlɛkʃən/ ]
定向选择
📖 定义
A form of selection that favors individuals at one extreme of a phenotypic range.
disruptive selection
[ /dɪsˈrəptɪv səˈlɛkʃən/ ]
分裂选择 / 歧化选择
📖 定义
A type of selection that favors individuals at both extremes of a trait, leading to a bimodal distribution.
stabilizing selection
[ /ˈsteɪbəˌlaɪzɪŋ səˈlɛkʃən/ ]
稳定选择
📖 定义
A mode of natural selection that favors intermediate phenotypic variants by acting against extreme phenotypes, reducing genetic and phenotypic variance within a population.
fossil
[ /ˈfɑsəl/ ]
化石
📖 定义
Preserved remains or traces of organisms that lived in the past.
biogeography
[ /bˌaɪoʊɡˌɑːfiːˈɑːriːə/ ]
生物地理学
📖 定义
The study of the distribution of species and ecosystems in geographic space and through geological time.
homologous structure
[ /hɑˈmɑləgəs ˈstrəkʧər/ ]
同源结构
📖 定义
Anatomical features that are similar in structure but may have different functions， indicating a common ancestry.
common ancestor (common ancestry)
[ /ˈkɑmən ˈænˌsɛstər/ ]
共同祖先
📖 定义
The shared ancestor of two or more species from which they evolved.
species
[ /ˈspiʃiz/ ]
物种
📖 定义
A group of organisms capable of interbreeding and producing viable, fertile offspring.
viable
[ /ˈvaɪəbəl/ ]
可存活的
📖 定义
Capable of surviving, developing normally, and maintaining metabolic independence in an environmental habitat.
fertile
[ /ˈfərtəl/ ]
具生殖能力的 / 可育的
📖 定义
Capable of producing viable, healthy gametes and successfully bearing offspring through sexual reproduction.
sympatric speciation
[ /sɪmpˈɑːtrɪk spˌɛʃiːˈeɪʃən/ ]
同域物种形成
📖 定义
The formation of new species within the same geographic area, often due to behavioral or ecological factors.
speciation
[ /spˌɛʃiːˈeɪʃən/ ]
物种形成
📖 定义
The evolutionary process by which new species arise.
reproductive isolation
[ /ˌriprəˈdəktɪv ˌaɪsəˈleɪʃən/ ]
生殖隔离
📖 定义
Barriers that prevent two populations from interbreeding and producing viable， fertile offspring.
allopatric speciation
[ /ˌæləpˈætrɪk spˌɛʃiːˈeɪʃən/ ]
异域物种形成
📖 定义
The formation of new species due to geographic isolation.
prezygotic barrier
[ /prˌɛdʒəzˈɔːtɪk ˈbɛriər/ ]
受精前隔离 / 合子前生殖隔离
📖 定义
A reproductive barrier that prevents fertilization from occurring between different species.
postzygotic barrier
[ /pˌoʊstiːɡzˈɑːtɪk ˈbɛriər/ ]
受精后隔离 / 合子后生殖隔离
📖 定义
A reproductive barrier that occurs after fertilization, often leading to inviable or sterile offspring.
geographical isolation
[ /ˌʤiəˈgræfɪkəl ˌaɪsəˈleɪʃən/ ]
地理隔离
📖 定义
A physical separation of populations by geographic barriers (mountains, rivers, canyons) that prevents gene flow and initiates allopatric speciation.
habitat isolation
[ /ˈhæbəˌtæt ˌaɪsəˈleɪʃən/ ]
栖息地隔离 / 生态隔离
📖 定义
A prezygotic reproductive barrier where two species inhabit different ecological niches within the same geographic area and rarely encounter each other to mate.
temporal isolation
[ /ˈtɛmpərəl ˌaɪsəˈleɪʃən/ ]
时间隔离 / 季节隔离
📖 定义
A prezygotic barrier in which related species breed at different times of the day, during different seasons, or in different years, preventing interbreeding.
behavioral isolation
[ /bɪˈheɪvjərəl ˌaɪsəˈleɪʃən/ ]
行为隔离
📖 定义
A prezygotic reproductive barrier characterized by differences in courtship rituals, vocalizations, or mating displays that prevent cross-mating between species.
mechanical isolation
[ /məˈkænɪkəl ˌaɪsəˈleɪʃən/ ]
机械隔离 / 形态隔离
📖 定义
A prezygotic barrier where anatomical and structural differences in reproductive organs physically prevent successful copulation or pollen transfer.
gametic isolation
[ /ɡəmˈɛtɪk ˌaɪsəˈleɪʃən/ ]
配子隔离
📖 定义
A prezygotic reproductive barrier where the sperm of one species is chemically incapable of fertilizing the egg of another species due to incompatible surface receptors.
reduced hybrid viability
[ /rɪˈdust ˈhaɪbrɪd vaɪəˈbɪləti/ ]
杂种存活率降低
📖 定义
A postzygotic barrier in which hybrid zygotes between two species fail to develop properly or survive to reproductive maturity due to genetic incompatibility.
reduced hybrid fertility
[ /rɪˈdust ˈhaɪbrɪd fərˈtɪlɪti/ ]
杂种不育 / 杂种育性降低
📖 定义
A postzygotic reproductive barrier where hybrid offspring develop into vigorous adults but are completely sterile due to failure in meiotic chromosome pairing (e.g., mules).
hybrid breakdown
[ /ˈhaɪbrɪd ˈbreɪkˌdaʊn/ ]
杂种衰败 / 杂种退化
📖 定义
A postzygotic barrier where first-generation (F1) interspecific hybrids are viable and fertile, but their offspring (F2) are feeble, malformed, or sterile.
punctuated equilibrium
[ /ˈpəŋkʧuˌeɪtɪd ˌiːkwɪˈlɪbriəm/ ]
间断平衡模式
📖 定义
The theory that evolutionary change occurs in rapid bursts followed by long periods ofstability.
gradualism
[ /ˈgræʤəwəˌlɪzəm/ ]
渐变模式 / 渐进式
📖 定义
The theory that evolution occurs through slow and steady changes over time.
divergent evolution
[ /dɪˈvərʤənt ˌɛvəˈluʃən/ ]
趋异进化
📖 定义
The process where related species evolve different traits, often due to different environments.
adaptive radiation
[ /əˈdæptɪv ˌreɪdiˈeɪʃən/ ]
适应辐射
📖 定义
The rapid evolution of diverse species from a common ancestor to exploit different ecological niches.
convergent evolution
[ /kənˈvərʤənt ˌɛvəˈluʃən/ ]
趋同进化
📖 定义
The process where unrelated species develop similar traits due to similar environmental pressures.
analogous structure
[ /əˈnæləgəs ˈstrəkʧər/ ]
同功结构
📖 定义
Structures with similar functions but different evolutionary origins.
coevolution
[ /kˌoʊvəwˈɛlʃən/ ]
协同进化
📖 定义
The reciprocal evolutionary influence between two or more species.
phylogeny
[ /faɪˈlɑːdʒəni/ ]
系统发生 / 种系发生
📖 定义
The evolutionary history and genealogical relationships of a species, higher taxon, or group of organisms over geological timescales.
phylogenetic tree
[ /fˌaɪələdʒənˈɛtɪk tri/ ]
系统发生树
📖 定义
A diagram that shows evolutionary relationships among species based on their common ancestry.
cladogram
[ /ˈklædəɡræm/ ]
进化分支图
📖 定义
A branching diagram that represents the evolutionary relationships among organisms based on shared characteristics.
outgroup
[ /ˌaʊtɡrˈʌp/ ]
外类群 / 外群
📖 定义
A species or group used for comparison that diverged before the species being studied.
extinction
[ /ɪkˈstɪŋʃən/ ]
生物灭绝
📖 定义
The permanent loss of all members of a species.
Hardy-Weinberg equilibrium
[ /ˈhɑːrdi ˈwaɪnbɜːrɡ ˌiːkwɪˈlɪbriəm/ ]
哈迪-温伯格平衡
📖 定义
A principle stating that allele frequencies in a population remain constant in the absence of evolutionary forces.
allele frequency
[ /əˈliːl ˈfrikwənsi/ ]
等位基因频率
📖 定义
The proportion of a specific allele in a population's gene pool.
genotype frequency
[ /ˈdʒiːnətaɪp ˈfrikwənsi/ ]
基因型频率
📖 定义
The proportion of individuals with a specific genotype in a population.
genetic drift
[ /ʤəˈnɛtɪk drɪft/ ]
遗传漂变
📖 定义
Random changes in allele frequencies in a population, especially in small populations.
bottleneck effect
[ /ˈbɑtəlˌnɛk ˈifɛkt/ ]
瓶颈效应
📖 定义
A severe reduction in genetic diversity occurring when a biological population undergoes an abrupt, drastic crash in size due to environmental catastrophes, overhunting, or habitat loss.
founder effect
[ /ˈfaʊndər ˈifɛkt/ ]
建立者效应 / 奠基者效应
📖 定义
Reduced genetic variation that occurs when a small group of individuals establishes a new population.
RNA world hypothesis
[ /rˈeɪn wərld haɪˈpɑθəsəs/ ]
RNA世界假说
📖 定义
The hypothesis that early life forms relied on RNA for both genetic information and catalytic functions.
gene flow
[ /ʤin floʊ/ ]
基因流 / 基因漂流
📖 定义
The transfer of alleles from one population to another.
Miller-Urey experiment
[ /ˈmɪlər ˈjʊəri ɪkˈspɛrɪmənt/ ]
米勒-尤里实验
📖 定义
A landmark 1953 origin-of-life simulation demonstrating that organic compounds, including amino acids, could abioticly synthesize from an inorganic reducing atmosphere.
ecology
[ /ɪˈkɑləʤi/ ]
生态学
📖 定义
The study of how organisms interact with each other and their environment.
organismal ecology
[ /ˈɔːrɡənzməsəl ɪˈkɑləʤi/ ]
机体生态学 / 个体生态学
📖 定义
The branch of ecology that studies how an organism's structure, physiology, and behavior help it survive and reproduce in its environment.
endotherm
[ /ˈɛndoʊθɜːrm/ ]
恒温动物 / 内温动物
📖 定义
An organism that generates its own body heat through internal metabolic processes to maintain a relatively stable internal temperature independently of the ambient environment.
ectotherm
[ /ˈɛktoʊθɜːrm/ ]
变温动物 / 外温动物
📖 定义
An organism that relies predominantly on external environmental heat sources (such as solar radiation) to regulate its internal body temperature.
altruism (altruistic behavior)
[ /ˈæltruˌɪzəm/ ]
利他行为
📖 定义
Behavior that benefits another individual at a cost to oneself.
kin selection
[ /kɪn səˈlɛkʃən/ ]
亲缘选择
📖 定义
A type of natural selection where individuals increase their genetic fitness by helping relatives reproduce.
population
[ /ˌpɑpjəˈleɪʃən/ ]
种群
📖 定义
A group of individuals of the same species living in the same area at the same time.
population growth
[ /ˌpɑpjəˈleɪʃən groʊθ/ ]
种群增长
📖 定义
The change in the number of individuals of a biological species in a defined habitat over time, governed by birth rates, death rates, immigration, and emigration.
exponential growth
[ /ˌɛkspoʊˈnɛnʃəl groʊθ/ ]
指数增长 (J型增长)
📖 定义
Rapid population increase in ideal conditions, represented by a J-shaped curve.
logistic growth
[ /ləˈʤɪstɪk groʊθ/ ]
逻辑斯谛增长 (S型增长)
📖 定义
Population growth that slows as it approaches the carrying capacity, forming an S-shaped curve.
density-dependent factor
[ /dˌɛnsɪtˈɪdpɪntɪd ˈfæktər/ ]
密度制约因素
📖 定义
A factor whose effect on population size increases as population density rises, such as disease or competition.
carrying capacity (K)
[ /ˈkæriɪŋ kəˈpæsɪti/ ]
环境容纳量 (K值)
📖 定义
The maximum number of individuals an environment can sustainably support.
density-independent factor
[ /dˌɛnsɪtˈɪntɪdənt ˈfæktər/ ]
非密度制约因素
📖 定义
A factor that affects population size regardless of density, such as weather or natural disasters.
community
[ /kəmˈjunɪti/ ]
生物群落
📖 定义
A group of interacting species living in the same area.
species composition
[ /ˈspiʃiz ˌkɑmpəˈzɪʃən/ ]
物种组成
📖 定义
The identity and relative abundance of all distinct biological species residing and interacting within a given ecological community.
species diversity
[ /ˈspiʃiz dɪˈvərsɪti/ ]
物种多样性
📖 定义
The variety of species in a community, including both richness and evenness.
species richness
[ /ˈspiʃiz ˈrɪʧnəs/ ]
物种丰富度
📖 定义
The total count of different biological species present in a defined ecological community or geographical area.
species evenness
[ /ˈspiʃiz ˈivənnəs/ ]
物种均匀度
📖 定义
A measure of the relative abundance and equitability of different biological species making up the total richness of an ecological community.
Simpson's diversity index
[ /ˈsɪmpsənz daɪˈvɜːrsɪti ˈɪndɛks/ ]
辛普森多样性指数
📖 定义
A mathematical quantitative metric (D = 1 - sum(n/N)^2) used to quantify biodiversity, taking into account both species richness and species evenness.
ecological niche
[ /ɛkəˈlɑʤɪkəl nɪʧ/ ]
生态位
📖 定义
The unique functional role, resource requirements, and environmental tolerance limits of a species within its ecosystem ('its ecological profession').
competition
[ /ˌkɑmpəˈtɪʃən/ ]
种间竞争
📖 定义
The struggle between organisms for the same limited resources in an ecosystem.
niche partitioning
[ /nɪʧ pɑrˈtɪʃənɪŋ/ ]
生态位分化 / 生态位隔离
📖 定义
The process by which competing species use resources in different ways to coexist.
predation
[ /prəˈdeɪʃən/ ]
捕食作用
📖 定义
A biological interaction in which one free-living organism (the predator) hunts, kills, and consumes another organism (the prey) for sustenance.
predator
[ /ˈprɛdətər/ ]
捕食者
📖 定义
An organism that naturally preys upon and consumes other organisms to obtain energy and nutrients.
prey
[ /preɪ/ ]
猎物 / 被捕食者
📖 定义
An animal hunted, caught, and consumed by a predator in a predator-prey relationship.
herbivory
[ /hˈɜːrbɪvˌɔːriː/ ]
植食作用 / 食草
📖 定义
A trophic interaction in which an herbivore consumes autotrophic plant tissues or algae without necessarily killing the whole plant organism.
herbivore
[ /ˈərbɪˌvɔr/ ]
植食性动物
📖 定义
A primary consumer adapted anatomically and physiologically to feed exclusively or primarily on autotrophic plants or algae.
carnivore
[ /ˈkɑrnɪˌvɔr/ ]
肉食性动物
📖 定义
A secondary or tertiary consumer that obtains nutritional energy primarily by eating animal tissue.
food chain
[ /fud ʧeɪn/ ]
食物链
📖 定义
A linear sequence showing how energy and nutrients flow from one organism to another.
food web
[ /fud wɛb/ ]
食物网
📖 定义
A complex network of interconnected food chains in an ecosystem.
producer (primary producer)
[ /prəˈdusər/ ]
生产者
📖 定义
An organism that creates its own food through photosynthesis or chemosynthesis.
consumer
[ /kənˈsumər/ ]
消费者
📖 定义
An organism that obtains energy by eating other organisms.
trophic level
[ /trˈɑːfɪk ˈlɛvəl/ ]
营养级
📖 定义
A step in the food chain or food web, representing an organism's position in the flow of energy.
photoautotroph
[ /fˌoʊtoʊˈeɪtərhəp/ ]
光能自养生物
📖 定义
An autotroph that uses sunlight to produce energy through photosynthesis.
chemoautotroph
[ /kˈɛməθˌɔːrəθ/ ]
化能自养生物
📖 定义
An autotroph that uses chemical energy to produce food through chemosynthesis.
autotroph
[ /ˈɔːtətrɑːf/ ]
自养生物
📖 定义
An organism that produces its own food from inorganic sources.
chemosynthesis
[ /kˌɛmoʊsˈɛnətsnəs/ ]
化能合成作用
📖 定义
The process by which certain organisms produce energy-rich compounds using chemical energy instead of light.
heterotroph
[ /ˈhɛtərətrɑːf/ ]
异养生物
📖 定义
An organism that obtains energy by consuming other organisms.
10% rule (ten percent law)
[ /rul/ ]
10%能量传递原则
📖 定义
The principle that only about 10% of the energy at one trophic level is transferred to the next.
bottom-up model
[ /ˈbɑtəˌməp ˈmɑdəl/ ]
自下而上调控模型
📖 定义
A model that suggests the availability of resources at the lowest trophic level determines the structure of the ecosystem.
top-down model
[ /ˈtɔpˌdaʊn ˈmɑdəl/ ]
自上而下调控模型
📖 定义
An ecological trophic control model postulating that predation by apex predators predominantly regulates the abundance, biomass, and diversity of lower trophic levels.
trophic pyramid
[ /trˈɑːfɪk ˈpɪrəmɪd/ ]
生态金字塔 / 营养级金字塔
📖 定义
A graphical representation of energy or biomass distribution among trophic levels.
trophic cascade
[ /trˈɑːfɪk kæˈskeɪd/ ]
营养级联效应
📖 定义
An ecological phenomenon triggered by the addition or removal of top predators, cascading reciprocal changes in predator-prey dynamics across two or more lower trophic levels.
symbiosis
[ /ˌsɪmbaɪˈoʊsɪs/ ]
共生关系
📖 定义
A close, long-term interaction between two different species.
mutualism
[ /ˈmjuːtʃuəlɪzəm/ ]
互利共生
📖 定义
A type of symbiosis where both species benefit from the interaction.
parasitism
[ /ˈpærəsɪtɪzəm/ ]
寄生
📖 定义
A type of symbiosis where one organism benefits while the other is harmed
parasite
[ /ˈpɛrəˌsaɪt/ ]
寄生生物 / 寄生虫
📖 定义
An organism that lives on or inside a host organism and benefits by deriving nutrients at the host organism's expense, often causing physiological harm.
host
[ /hoʊst/ ]
宿主 / 寄主
📖 定义
An organism that harbors and provides nutritional sustenance or shelter to a symbiotic parasite or mutualistic organism.
commensalism
[ /kəˈmɛnsəlɪzəm/ ]
偏利共生 (共栖)
📖 定义
A type of symbiosis where one organism benefits and the other is neither helped nor harmed.
decomposer
[ /dˌiːkəmpˈoʊzər/ ]
分解者
📖 定义
An organism (such as fungi and bacteria) that digests and breaks down dead organic matter and metabolic wastes into essential inorganic nutrients, recycling them through the ecosystem.
decomposition
[ /ˌdikəmpəˈzɪʃən/ ]
分解作用
📖 定义
The process by which decomposers break down dead organisms and recycle nutrients back into the ecosystem.
keystone species
[ /ˈkiˌstoʊn ˈspiʃiz/ ]
关键物种
📖 定义
A species that has a disproportionately large effect on its ecosystem relative to its abundance.
ecosystem
[ /ˈikoʊˌsɪstəm/ ]
生态系统
📖 定义
A biological community and its physical environment interacting as a system.
biotic factor
[ /bˌaɪətˈɛk ˈfæktər/ ]
生物因素
📖 定义
A living component of an ecosystem, such as plants or animals.
ecosystem diversity
[ /ˈikoʊˌsɪstəm dɪˈvərsɪti/ ]
生态系统多样性
📖 定义
The variety of biological communities, habitats, and ecological processes operating within a given geographical region or biome.
abiotic factor
[ /ˌæbiːˈɑːtɪk ˈfæktər/ ]
非生物因素
📖 定义
A non-living component of an ecosystem, such as sunlight, water, or temperature.
biodiversity
[ /ˌbaɪoʊdaɪˈvərsəti/ ]
生物多样性
📖 定义
The variety of life in all its forms, levels, and combinations within an ecosystem.
invasive species
[ /ˌɪnˈveɪsɪv ˈspiʃiz/ ]
入侵物种
📖 定义
A non-native species that spreads rapidly and causes harm to ecosystems.
| 生物单词 (Term) | 国际音标 (IPA) | 中文释义 (Translation) | 英文详细定义 (Definition) | 单元 (Unit) |
|---|---|---|---|---|
| nonpolar molecule | [ /nɑːnpˈɑːlər ˈmɑləˌkjul/ ] | 非极性分子 |
A molecule that lacks a net electric charge or dipole moment due to equal sharing of electrons or symmetrical molecular geometry, making it hydrophobic.
|
Unit 1 |
| polar molecule | [ /ˈpoʊlər ˈmɑləˌkjul/ ] | 极性分子 |
A molecule (such as water) with an uneven distribution of charges in different regions of the molecule, resulting in partially positive and partially negative poles.
|
Unit 1 |
| hydrogen bond | [ /ˈhaɪdrəʤən bɑnd/ ] | 氢键 |
A weak bond formed between a partially positive hydrogen atom and a partially negative atom, like oxygen or nitrogen, in different molecules or within a large molecule.
|
Unit 1 |
| cohesion | [ /koʊˈhiʒən/ ] | 内聚力 |
The attraction between molecules of the same substance, often seen in water due to hydrogen bonding.
|
Unit 1 |
| adhesion | [ /æˈdhiʒən/ ] | 粘附力 |
The attraction between molecules of different substances, such as water adhering to plant cell walls.
|
Unit 1 |
| surface tension | [ /ˈsərfəs ˈtɛnʃən/ ] | 表面张力 |
The cohesive forces at the surface of a liquid that allow it to resist external forces and form a "skin."
|
Unit 1 |
| specific heat / heat capacity | [ /spɪˈsɪfɪk hit / hit kəˈpæsɪti/ ] | 比热容 |
The amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius.
|
Unit 1 |
| heat of vaporization | [ /hit əv veɪpərəˈzeɪʃən/ ] | 汽化热 / 气化潜热 |
The amount of heat required to convert one gram of a liquid into vapor without a temperature change.
|
Unit 1 |
| boiling point | [ /ˈbɔɪlɪŋ pɔɪnt/ ] | 沸点 |
The temperature at which the vapor pressure of a liquid equals the external atmospheric pressure, requiring substantial thermal energy to break intermolecular hydrogen bonds in water.
|
Unit 1 |
| hydrophilic | [ /ˌhaɪdrəˈfɪlɪk/ ] | 亲水的 |
Substances that interact well with water, often due to polar or charged properties.
|
Unit 1 |
| hydrophobic | [ /ˌhaɪdrəˈfoʊbɪk/ ] | 疏水的 |
Substances that repel water, typically nonpolar and unable to form hydrogen bonds.
|
Unit 1 |
| organic molecule | [ /ɔrˈgænɪk ˈmɑləˌkjul/ ] | 有机分子 |
A chemical compound that contains carbon atoms covalently bonded to hydrogen and often other elements such as oxygen, nitrogen, and phosphorus.
|
Unit 1 |
| macromolecule | [ /ˌmækroʊˈmɑːlɪkjuːl/ ] | 生物大分子 |
A giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction; includes carbohydrates, lipids, proteins, and nucleic acids.
|
Unit 1 |
| monomer | [ /ˈmɑnəmər/ ] | 单体 |
A small molecule that can bind chemically to form larger molecules.
|
Unit 1 |
| polymer | [ /ˈpɑləmər/ ] | 多聚体 / 聚合物 |
A large molecule composed of repeating monomeric units linked by covalent bonds.
|
Unit 1 |
| dehydration reaction / dehydration synthesis / condensation | [ /ˌdihaɪˈdreɪʃən riˈækʃən / ˌdihaɪˈdreɪʃən ˈsɪnθəsɪs / ˌkɑːndɛnˈseɪʃən/ ] | 脱水缩合反应 |
A chemical reaction in which two molecules are joined by covalent bonds with the removal of a water molecule.
|
Unit 1 |
| hydrolysis | [ /haɪˈdrɑːləsɪs/ ] | 水解反应 |
A chemical reaction in which water is used to break bonds between molecules.
|
Unit 1 |
| carbohydrates | [ /ˌkɑrboʊˈhaɪdreɪts/ ] | 碳水化合物 / 糖类 |
Organic compounds composed of carbon, hydrogen, and oxygen, primarily used for energy storage and structural purposes.
|
Unit 1 |
| monosaccharide | [ /ˌmɑːnoʊˈsækəraɪd/ ] | 单糖 |
The simplest form of carbohydrate, consisting of a single sugar molecule.
|
Unit 1 |
| glucose | [ /ˈɡluːkoʊs/ ] | 葡萄糖 |
A six-carbon monosaccharide (hexose) with the molecular formula C6H12O6; serves as the primary substrate for cellular respiration and a monomer for glycogen, starch, and cellulose.
|
Unit 1 |
| galactose | [ /ɡəˈlæktoʊs/ ] | 半乳糖 |
A six-carbon aldose monosaccharide that is a stereoisomer of glucose; combines with glucose via a beta-1,4-glycosidic bond to form the disaccharide lactose.
|
Unit 1 |
| fructose | [ /ˈfrʊktoʊs/ ] | 果糖 |
A six-carbon keto-hexose monosaccharide found commonly in fruits and honey; combines with glucose via an alpha-1,beta-2-glycosidic bond to form sucrose.
|
Unit 1 |
| disaccharide | [ /daɪˈsækəraɪd/ ] | 二糖 |
A carbohydrate composed of two monosaccharides linked by a glycosidic bond.
|
Unit 1 |
| maltose | [ /ˈmɔːltoʊs/ ] | 麦芽糖 |
A disaccharide composed of two glucose molecules linked by an alpha-1,4-glycosidic bond; produced during the enzymatic breakdown of starch.
|
Unit 1 |
| sucrose | [ /ˈsuːkroʊs/ ] | 蔗糖 |
A common disaccharide (table sugar) consisting of one glucose and one fructose molecule linked by a glycosidic bond; major transport form of sugar in plants.
|
Unit 1 |
| lactose | [ /ˈlæktoʊs/ ] | 乳糖 |
A disaccharide composed of one galactose and one glucose unit joined by a beta-1,4-glycosidic linkage; the primary carbohydrate found in mammalian milk.
|
Unit 1 |
| polysaccharide | [ /ˌpɑːliˈsækəraɪd/ ] | 多糖 |
A complex carbohydrate consisting of long chains of monosaccharide units.
|
Unit 1 |
| starch | [ /stɑrʧ/ ] | 淀粉 |
A storage polysaccharide in plants consisting entirely of glucose monomers linked by alpha-1,4 and alpha-1,6 glycosidic bonds (composed of amylose and amylopectin).
|
Unit 1 |
| glycogen | [ /ˈɡlaɪkədʒən/ ] | 糖原 |
An extensively branched storage polysaccharide of glucose found in animal liver and muscle tissues; hydrolyzed to release glucose when metabolic demand increases.
|
Unit 1 |
| cellulose | [ /ˈsɛljʊloʊs/ ] | 纤维素 |
A structural polysaccharide of plant cell walls consisting of straight, unbranched beta-1,4-linked glucose chains bundled into rigid, insoluble microfibrils.
|
Unit 1 |
| lipids | [ /lˈɪpədz/ ] | 脂质 / 脂类 |
A group of hydrophobic organic molecules, including fats, oils, and steroids, that are used for energy storage and cell membrane structure.
|
Unit 1 |
| fatty acid | [ /ˈfæti ˈæsəd/ ] | 脂肪酸 |
A carboxylic acid with a long hydrocarbon chain, a key component of lipids.
|
Unit 1 |
| hydrocarbon chain | [ /ˌhaɪdroʊˈkɑrbən ʧeɪn/ ] | 碳氢链 |
A nonpolar chain of covalently bonded carbon and hydrogen atoms, such as the fatty acid tail of lipids, that is hydrophobic and energy-rich.
|
Unit 1 |
| unsaturated fatty acid | [ /ənˈsæʧərˌeɪtɪd ˈfæti ˈæsəd/ ] | 不饱和脂肪酸 |
A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail, creating kinks that prevent tight packing and keeping them liquid at room temperature.
|
Unit 1 |
| saturated fatty acid | [ /ˈsæʧərˌeɪtɪd ˈfæti ˈæsəd/ ] | 饱和脂肪酸 |
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, maximizing the number of hydrogen atoms attached and typically solid at room temperature.
|
Unit 1 |
| glycerol | [ /ˈglɪsərˌoʊl/ ] | 甘油 |
A three-carbon alcohol with three hydroxyl (-OH) groups that forms the covalent backbone of triglycerides and phospholipids through ester linkages.
|
Unit 1 |
| triglyceride | [ /traɪˈɡlɪsəraɪd/ ] | 甘油三酯 |
A lipid molecule made up of one glycerol and three fatty acid chains.
|
Unit 1 |
| phospholipid | [ /ˌfɑːsfoʊˈlɪpɪd/ ] | 磷脂 |
A lipid containing a phosphate group and two fatty acid tails, essential for cell membranes.
|
Unit 1 |
| phosphate group | [ /ˈfɑsfeɪt grup/ ] | 磷酸基团 |
A functional group (-PO4^2-) consisting of a phosphorus atom covalently bonded to four oxygen atoms; critical in energy transfer (ATP), nucleic acid backbones, and phospholipid membranes.
|
Unit 1 |
| phospholipid bilayer | [ /ˌfɑːsfoʊˈlɪpɪd ˈbaɪleɪər/ ] | 磷脂双分子层 |
The double-layered structure of cell membranes formed by phospholipids, with hydrophilic heads outward and hydrophobic tails inward
|
Unit 1 |
| steroid | [ /stərɔɪd/ ] | 类固醇 / 固醇类 |
A type of lipid with a characteristic four-ring structure, functioning as hormones or membrane components.
|
Unit 1 |
| cholesterol | [ /kəˈlɛstərˌɔl/ ] | 胆固醇 |
A steroid that is a key component of cell membranes and a precursor for other steroid hormones.
|
Unit 1 |
| hormone | [ /ˈhɔrˌmoʊn/ ] | 激素 / 荷尔蒙 |
A secreted signaling molecule in multicellular organisms that travels in body fluids to act on specific target cells to coordinate physiology and behavior.
|
Unit 1 |
| protein | [ /ˈproʊˌtin/ ] | 蛋白质 |
A macromolecule composed of amino acids, essential for various biological functions including enzymes, structure, and signaling.
|
Unit 1 |
| amino acid | [ /əˈminoʊ ˈæsəd/ ] | 氨基酸 |
The building block of proteins, consisting of an amino group, a carboxyl group, and a unique side chain.
|
Unit 1 |
| R group | [ /ɑr grup/ ] | R基 (侧链基团) |
The variable side chain attached to the alpha-carbon of an amino acid that confers its distinctive chemical properties (polar, nonpolar, acidic, or basic).
|
Unit 1 |
| side chain | [ /saɪd ʧeɪn/ ] | 侧链 |
Alternative term for the R group of an amino acid; determines the tertiary folding pattern and chemical reactivity of a protein.
|
Unit 1 |
| backbone | [ /ˈbækˌboʊn/ ] | 主链 / 骨架 |
The repeating structural chain of a polymer, such as the sugar-phosphate chain in nucleic acids or the N-C-C chain in polypeptide backbones.
|
Unit 1 |
| peptide bond | [ /ˈpɛpˌtaɪd bɑnd/ ] | 肽键 |
A covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
|
Unit 1 |
| polypeptide | [ /pˌɑːliːpˈɛptədˌaɪd/ ] | 多肽 |
A chain of amino acids linked by peptide bonds, which folds to form a protein.
|
Unit 1 |
| amino-end (N-terminus) | [ /ˈæmɪnˌoʊdn/ ] | 氨基端 (N端) |
The end of a polypeptide chain that terminates with an unbound, free amino group (-NH2 or -NH3+); represents the start of protein synthesis.
|
Unit 1 |
| carboxyl-end (C-terminus) | [ /kˈɑːrbəklˌɪst/ ] | 羧基端 (C端) |
The end of a polypeptide chain that terminates with an unbound, free carboxyl group (-COOH or -COO-); represents the terminus where new amino acids are added.
|
Unit 1 |
| primary structure | [ /ˈpraɪˌmɛri ˈstrəkʧər/ ] | 一级结构 |
The linear sequence of amino acids in a protein.
|
Unit 1 |
| secondary structure | [ /ˈsɛkənˌdɛri ˈstrəkʧər/ ] | 二级结构 |
Localized folding of a polypeptide into structures like alpha-helices and beta- sheets, stabilized by hydrogen bonds.
|
Unit 1 |
| alpha-helix (α-helix) | [ /ˈælfəlˌɛkəlz/ ] | α螺旋 |
A secondary structure of proteins consisting of a coiled polypeptide chain stabilized by hydrogen bonds between the carbonyl oxygen and amide hydrogen four residues apart.
|
Unit 1 |
| beta-pleated sheet (β-pleated sheet) | [ /bˈiːtəplˌeɪtəd ʃit/ ] | β折叠 |
A secondary protein structure in which two or more parallel or antiparallel polypeptide strands are held together by hydrogen bonds between backbone atoms.
|
Unit 1 |
| tertiary structure | [ /ˈtərʃəri ˈstrəkʧər/ ] | 三级结构 |
The overall three-dimensional shape of a protein formed by interactions between side chains.
|
Unit 1 |
| disulfide bridge | [ /dɪsˈʌləfˌaɪd brɪʤ/ ] | 二硫键 |
A strong covalent bond formed between the sulfhydryl (-SH) groups of two cysteine residues; stabilizes the tertiary and quaternary structures of proteins.
|
Unit 1 |
| quaternary structure | [ /kˈwɑtərˌnɛri ˈstrəkʧər/ ] | 四级结构 |
The structure formed when multiple polypeptides interact to form a functional protein.
|
Unit 1 |
| hemoglobin | [ /ˌhiməˈgloʊbən/ ] | 血红蛋白 |
An iron-containing quaternary protein in red blood cells consisting of two alpha and two beta globin subunits that transports oxygen from lungs to tissues.
|
Unit 1 |
| denaturation | [ /dɪnˈækjətrˈeɪʃən/ ] | （蛋白质）变性 |
A process in which a protein loses its native three-dimensional tertiary/secondary structure due to disruption of weak chemical bonds and interactions by heat, extreme pH, or chemical agents, rendering it biologically inactive.
|
Unit 1 |
| alpha-globin (α-globin) | [ /ˌælfəɡˈɑːlbən/ ] | α珠蛋白 |
One of the two primary polypeptide subunit types that compose adult hemoglobin, encoded by genes on human chromosome 16.
|
Unit 1 |
| beta-globin (β-globin) | [ /bɪtˈɑːɡlən/ ] | β珠蛋白 |
One of the two primary polypeptide subunit types that compose adult hemoglobin, encoded by genes on human chromosome 11; mutated in sickle cell disease.
|
Unit 1 |
| DNA (deoxyribonucleic acid) | [ /ˈdiˌɛˈneɪ/ ] | 脱氧核糖核酸 |
A double-stranded, helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose and the bases A, T, C, G; stores hereditary information.
|
Unit 1 |
| nucleic acid | [ /nuˈkleɪɪk ˈæsəd/ ] | 核酸 |
A macromolecule that stores genetic information, such as DNA and RNA.
|
Unit 1 |
| renaturation | [ /rɪnˈætʃərətˈeɪn/ ] | （蛋白质）复性 |
The refolding of a denatured, biologically inactive protein back into its native, biologically active three-dimensional conformation upon restoration of physiological conditions.
|
Unit 1 |
| nucleotide | [ /ˈnuːkliətaɪd/ ] | 核苷酸 |
The building block of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.
|
Unit 1 |
| deoxyribose | [ /diːˌɑːksɪˈraɪboʊs/ ] | 脱氧核糖 |
The five-carbon pentose sugar found in DNA nucleotides, which lacks a hydroxyl group at the 2' carbon position (contains -H instead of -OH).
|
Unit 1 |
| ribose | [ /ˈraɪboʊs/ ] | 核糖 |
The five-carbon pentose sugar present in RNA nucleotides and ATP, containing a hydroxyl group (-OH) attached to the 2' carbon position.
|
Unit 1 |
| nitrogenous base | [ /naɪˈtrɑʤənəs beɪs/ ] | 含氮碱基 |
A nitrogen-containing organic molecule with basic properties that forms the informational component of nucleotides; classified into purines and pyrimidines.
|
Unit 1 |
| pyrimidine | [ /pˌɪrɪmˈɪdiːn/ ] | 嘧啶 |
A class of nitrogenous bases characterized by a single six-membered carbon-nitrogen ring; includes cytosine (C), thymine (T), and uracil (U).
|
Unit 1 |
| purine | [ /pʊrˈiːniː/ ] | 嘌呤 |
A class of nitrogenous bases characterized by a fused six-membered and five-membered carbon-nitrogen double ring; includes adenine (A) and guanine (G).
|
Unit 1 |
| cytosine | [ /ˈsaɪtəsiːn/ ] | 胞嘧啶 |
A pyrimidine nitrogenous base found in both DNA and RNA that forms three hydrogen bonds with guanine during base pairing.
|
Unit 1 |
| thymine | [ /ˈθaɪmiːn/ ] | 胸腺嘧啶 |
A pyrimidine nitrogenous base found exclusively in DNA that pairs with adenine via two hydrogen bonds.
|
Unit 1 |
| uracil | [ /ˈjʊrəsɪl/ ] | 尿嘧啶 |
A pyrimidine nitrogenous base found exclusively in RNA that pairs with adenine via two hydrogen bonds during transcription and translation.
|
Unit 1 |
| adenine | [ /ˈædənɪn/ ] | 腺嘌呤 |
A purine nitrogenous base found in DNA, RNA, and ATP that pairs with thymine in DNA (two hydrogen bonds) and uracil in RNA.
|
Unit 1 |
| guanine | [ /ˈɡwɑːniːn/ ] | 鸟嘌呤 |
A purine nitrogenous base found in DNA and RNA that forms three hydrogen bonds with cytosine during complementary base pairing.
|
Unit 1 |
| sugar-phosphate backbone | [ /saɪɡˈʌsprəhˌeɪts ˈbækˌboʊn/ ] | 糖-磷酸骨架 |
The alternating chain of sugar and phosphate units linked by covalent phosphodiester bonds that forms the structural structural sides of a nucleic acid strand.
|
Unit 1 |
| 3' end | [ /ɛnd/ ] | 3'端 (3号碳端) |
The terminus of a nucleic acid strand terminating in a free hydroxyl group (-OH) attached to the 3' carbon of the terminal pentose sugar.
|
Unit 1 |
| 5' end | [ /ɛnd/ ] | 5'端 (5号碳端) |
The terminus of a nucleic acid strand terminating in a free phosphate group attached to the 5' carbon of the terminal pentose sugar.
|
Unit 1 |
| base pairing | [ /beɪs ˈpɛrɪŋ/ ] | 碱基互补配对 |
The specific hydrogen bonding between complementary bases in DNA or RNA （e.g.， A-T or A-U, and G-C）.
|
Unit 1 |
| base sequence | [ /beɪs ˈsikwəns/ ] | 碱基序列 |
The specific order of nitrogenous bases in a nucleic acid, encoding genetic information.
|
Unit 1 |
| antiparallel | [ /ˌæntəpˈɑːrələ/ ] | 反向平行 |
The opposite orientation of the two strands in a DNA double helix.
|
Unit 1 |
| double helix | [ /ˈdəbəl ˈhiːlɪks/ ] | 双螺旋 |
The spiral-shaped structure formed by two strands of DNA held together by base pairing.
|
Unit 1 |
| prokaryotic cell | [ /proʊˌkæriˈɑːtɪk sɛl/ ] | 原核细胞 |
A cell without a nucleus or membrane-bound organelles, characteristic of bacteria and archaea.
|
Unit 2 |
| eukaryotic cell | [ /juːˌkæriˈɑːtɪk sɛl/ ] | 真核细胞 |
A cell with a nucleus and membrane-bound organelles, found in plants, animals， fungi,and protists.
|
Unit 2 |
| bacterium / bacteria | [ /bækˈtɪriəm / bækˈtɪriə/ ] | 细菌 |
Single-celled prokaryotic microorganisms that possess peptidoglycan cell walls, circular DNA, and 70S ribosomes, lacking membrane-bound organelles.
|
Unit 2 |
| archaea | [ /ɑːrkˈeɪə/ ] | 古菌 |
A domain of single-celled prokaryotes biochemically distinct from bacteria, often inhabiting extreme environments (extremophiles) and having unique ether-linked membrane lipids.
|
Unit 2 |
| animal | [ /ˈænəməl/ ] | 动物 |
A kingdom of multicellular, heterotrophic eukaryotic organisms that ingest other organisms, lack cell walls, and possess differentiated tissues.
|
Unit 2 |
| plant | [ /plænt/ ] | 植物 |
A kingdom of multicellular, autotrophic eukaryotic organisms with cellulose cell walls, chloroplasts for photosynthesis, and alternation of generations.
|
Unit 2 |
| fungus / fungi | [ /ˈfəŋgəs / ˈfənʤaɪ/ ] | 真菌 |
A kingdom of heterotrophic eukaryotes that absorb nutrients from their surroundings via hyphae, possess chitinous cell walls, and act as major decomposers.
|
Unit 2 |
| protist | [ /prˈoʊtɪst/ ] | 原生生物 |
A diverse, non-monophyletic paraphyletic group of mostly unicellular eukaryotes that are not animals, plants, or fungi (e.g., amoebas, paramecia, algae).
|
Unit 2 |
| cell membrane / plasma membrane | [ /sɛl ˈmɛmˌbreɪn / ˈplæzmə ˈmɛmˌbreɪn/ ] | 细胞膜 / 质膜 |
A selectively permeable barrier that surrounds the cell, controlling the movement of substances in and out.
|
Unit 2 |
| cytoplasm | [ /ˈsaɪtəplæzəm/ ] | 细胞质 |
The region of the cell between the plasma membrane and the nucleus, containing organelles and the cytosol.
|
Unit 2 |
| cytosol | [ /ˈsaɪtəsɑːl/ ] | 细胞质基质 |
The gel-like substance within the cytoplasm where organelles and cellular components are suspended.
|
Unit 2 |
| nucleus | [ /ˈnukliəs/ ] | 细胞核 |
The membrane-bound organelle that houses the cell's DNA and controls its activities.
|
Unit 2 |
| membrane-bound organelle | [ /mˌɛmbrəndˈænb ˌɔːrɡənˈɛl/ ] | 膜结合细胞器 |
An organelle enclosed by a lipid bilayer, such as the nucleus, mitochondria, or Golgi apparatus.
|
Unit 2 |
| nucleoid | [ /nˈuːklˌɔɪd/ ] | 拟核 |
The region in a prokaryotic cell where the DNA is located, not enclosed by a membrane.
|
Unit 2 |
| organelle | [ /ˌɔːrɡənˈɛl/ ] | 细胞器 |
A specialized structure within a cell that performs specific functions.
|
Unit 2 |
| fluid mosaic model | [ /fluɪd moʊˈzeɪɪk ˈmɑdəl/ ] | 流动镶嵌模型 |
A model describing the structure of the plasma membrane as a flexible bilayer with embedded proteins.
|
Unit 2 |
| compartmentalization | [ /kˌɑːmpˌɑːrtəmpʃənˈɛtləsniː/ ] | 区室化 |
The organization of cellular activities into specialized, membrane-bound compartments.
|
Unit 2 |
| glycoprotein | [ /ɡlˈaɪkrəpˌɔɪtn/ ] | 糖蛋白 |
A membrane or secretory protein covalently bonded to one or more carbohydrate oligosaccharide chains, crucial for cell-cell recognition and immune signaling.
|
Unit 2 |
| glycolipid | [ /ɡlˈaɪkəlˌaɪds/ ] | 糖脂 |
A lipid molecule covalently attached to one or more carbohydrate chains, embedded in the plasma membrane and involved in cell recognition and membrane stability.
|
Unit 2 |
| cell-cell recognition | [ /sˈɛltʃˌɛl ˌrɛkɪgˈnɪʃən/ ] | 细胞间识别 |
The ability of a cell to distinguish neighboring cells by binding to surface molecules (often glycoproteins or glycolipids) on the extracellular plasma membrane.
|
Unit 2 |
| intercellular joining | [ /ˌɪntərˈsɛljələr ˈʤɔɪnɪŋ/ ] | 细胞间连接 |
Membrane proteins of adjacent cells that hook together in various junctions (such as tight junctions, gap junctions, or desmosomes) to facilitate adhesion and communication.
|
Unit 2 |
| selective permeability | [ /səˈlɛktɪv pərˌmiəˈbɪlɪti/ ] | 选择透过性 |
A fundamental property of biological membranes that allows them to regulate the passage of substances across them, permitting certain molecules to enter or exit while excluding others.
|
Unit 2 |
| passive transport | [ /ˈpæsɪv ˈtrænspɔrt/ ] | 被动运输 |
The movement of substances across a membrane without the use of energy, down their concentration gradient.
|
Unit 2 |
| simple diffusion | [ /ˈsɪmpəl dɪfˈjuʒən/ ] | 简单扩散 / 自由扩散 |
The movement of molecules directly across the membrane down their concentration gradient.
|
Unit 2 |
| facilitated diffusion | [ /fəˈsɪləˌteɪtɪd dɪfˈjuʒən/ ] | 易化扩散 / 协助扩散 |
The passive movement of molecules across a membrane through transport proteins.
|
Unit 2 |
| transport protein | [ /ˈtrænspɔrt ˈproʊˌtin/ ] | 转运蛋白 |
A transmembrane protein (such as a channel or carrier) that assists a specific polar molecule or ion in crossing the hydrophobic plasma membrane.
|
Unit 2 |
| channel protein | [ /ˈʧænəl ˈproʊˌtin/ ] | 通道蛋白 |
A transmembrane transport protein that provides a hydrophilic passageway allowing specific water-soluble molecules or ions to diffuse rapidly across the hydrophobic lipid bilayer.
|
Unit 2 |
| carrier protein | [ /ˈkɛriər ˈproʊˌtin/ ] | 载体蛋白 |
A transport protein that binds specific solute molecules and undergoes conformational changes to shuttle them across the biological membrane down or against their concentration gradient.
|
Unit 2 |
| osmosis | [ /ɑːzˈmoʊsɪs/ ] | 渗透作用 |
The diffusion of water across a selectively permeable membrane from a region of lower solute concentration to higher solute concentration.
|
Unit 2 |
| aquaporin | [ /ˈækwəpˌɔːrn/ ] | 水通道蛋白 |
A specialized channel protein in the plasma membrane that facilitates the rapid, selective passage of water molecules by osmosis.
|
Unit 2 |
| hypotonic | [ /hˌaɪpətˈɑːnɪk/ ] | 低渗的 |
A solution with a lower solute concentration compared to another, causing water to enter a cell.
|
Unit 2 |
| hypertonic | [ /ˌhaɪpərˈtɑnɪk/ ] | 高渗的 |
A solution with a higher solute concentration compared to another, causing water to leave a cell.
|
Unit 2 |
| isotonic | [ /ˌaɪsəˈtɑnɪk/ ] | 等渗的 |
A solution with the same solute concentration as another, resulting in no net water movement.
|
Unit 2 |
| osmoregulation | [ /ˌɑːzmoʊˌrɛɡjʊˈleɪʃən/ ] | 渗透调节 |
The process by which organisms maintain water and solute balance within their bodies or cells.
|
Unit 2 |
| water potential | [ /ˈwɔtər pəˈtɛnʃəl/ ] | 水势 |
A measure of the potential energy in water, determining the direction of its movement.
|
Unit 2 |
| pressure potential | [ /ˈprɛʃər pəˈtɛnʃəl/ ] | 压力势 |
A component of water potential that represents the physical pressure exerted on a solution; positive in turgid plant cells, negative under tension (transpiration).
|
Unit 2 |
| primary active transport | [ /ˈpraɪˌmɛri ˈæktɪv ˈtrænspɔrt/ ] | 初级主动运输 |
Active transport that directly uses energy, typically from ATP, to move substances.
|
Unit 2 |
| solute potential | [ /sˈoʊluːt pəˈtɛnʃəl/ ] | 溶质势 |
A component of water potential that is directly proportional to the molarity of a solution and is always zero or negative; reduces water potential as solute concentration rises.
|
Unit 2 |
| active transport | [ /ˈæktɪv ˈtrænspɔrt/ ] | 主动运输 |
The movement of substances across a membrane against their concentration gradient, requiring energy.
|
Unit 2 |
| secondary active transport | [ /ˈsɛkənˌdɛri ˈæktɪv ˈtrænspɔrt/ ] | 次级主动运输 |
Active transport that uses the energy from an existing gradient established by primary active transport.
|
Unit 2 |
| Na+/K+ pump (Na+/K+ ATPase) | [ /nɑ / keɪ pəmp nɑ / keɪ ˈætpˌeɪs/ ] | 钠钾泵 |
An electrogenic transmembrane transport protein that hydrolyzes ATP to actively pump 3 Na+ out of the cell and 2 K+ into the cell against their concentration gradients.
|
Unit 2 |
| endocytosis | [ /ˌɛndoʊsaɪˈtoʊsɪs/ ] | 胞吞作用 |
The process of taking substances into the cell by engulfing them in vesicles.
|
Unit 2 |
| exocytosis | [ /ˌɛksoʊsaɪˈtoʊsɪs/ ] | 胞吐作用 |
The process of expelling substances from the cell by vesicles fusing with the plasma membrane.
|
Unit 2 |
| vesicle | [ /ˈvɛsɪkəl/ ] | 囊泡 / 小泡 |
A small, membrane-bound sac used for transport or storage within a cell.
|
Unit 2 |
| nuclear envelope | [ /ˈnukliər ˈɛnvəˌloʊp/ ] | 核膜 |
A double membrane perforated with protein-lined nuclear pores that encloses the nucleus, separating genetic material from the cytoplasm in eukaryotic cells.
|
Unit 2 |
| nucleolus | [ /njuːˈkliːələs/ ] | 核仁 |
A dense region inside the non-dividing eukaryotic nucleus where ribosomal RNA (rRNA) is synthesized and assembled with ribosomal proteins into ribosome subunits.
|
Unit 2 |
| nuclear pore | [ /ˈnukliər pɔr/ ] | 核孔 |
A large protein complex spanning the double membrane of the nuclear envelope that regulates molecular trafficking (mRNA, proteins) between nucleus and cytoplasm.
|
Unit 2 |
| chromatin | [ /ˈkroʊmətɪn/ ] | 染色质 |
The complex of DNA and proteins in a loose form that forms chromosomes within the nucleus.
|
Unit 2 |
| ribosome | [ /ˈraɪbəsoʊm/ ] | 核糖体 |
A cellular structure that synthesizes proteins by translating messenger RNA.
|
Unit 2 |
| large subunit | [ /lɑrʤ səbˈiːnɪt/ ] | 大亚基 |
The larger of the two ribonucleoprotein complexes forming a functional ribosome; catalyzes peptide bond formation at its peptidyl transferase center.
|
Unit 2 |
| small subunit | [ /smɔl səbˈiːnɪt/ ] | 小亚基 |
The smaller ribonucleoprotein ribosomal subunit that binds mRNA and mediates base pairing between mRNA codons and tRNA anticodons.
|
Unit 2 |
| ribosomal RNA (rRNA) | [ /ˌraɪbəˈsoʊməl ˌɑːr.ɛnˈeɪ/ ] | 核糖体RNA |
RNA molecules that, together with proteins, make up ribosomes; some rRNAs have catalytic enzymatic activity (ribozymes) in peptide bond synthesis.
|
Unit 2 |
| free ribosome | [ /fri ˈraɪbəsoʊm/ ] | 游离核糖体 (悬浮核糖体) |
A ribosome suspended in the cytosol that synthesizes proteins destined to function primarily within the cytoplasm of the cell.
|
Unit 2 |
| attached ribosome | [ /əˈtæʧt ˈraɪbəsoʊm/ ] | 附着核糖体 (黏附核糖体) |
A ribosome bound to the cytosolic surface of the rough endoplasmic reticulum or outer nuclear membrane, synthesizing proteins destined for insertion into membranes, organelle packaging, or secretion.
|
Unit 2 |
| smooth endoplasmic reticulum (smooth ER) | [ /smuð ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ] | 滑面内质网 |
The portion of the ER without ribosomes, involved in lipid synthesis and detoxification.
|
Unit 2 |
| endoplasmic reticulum (ER) | [ /ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ] | 内质网 |
A network of membranes involved in protein and lipid synthesis.
|
Unit 2 |
| rough endoplasmic reticulum (rough ER) | [ /rəf ˌɛndoʊˈplæzmɪk rɪˈtɪkjʊləm/ ] | 粗面内质网 |
The portion of the ER studded with ribosomes, involved in protein synthesis and modification.
|
Unit 2 |
| Golgi apparatus (body / complex) | [ /ˈgoʊlʤi ˌæpərˈætəs ˈbɑdi / ˈkɑmplɛks/ ] | 高尔基体 |
A membrane-bound organelle that modifies, sorts, and packages proteins and lipids for transport.
|
Unit 2 |
| lysosome | [ /ˈlaɪsəsoʊm/ ] | 溶酶体 |
A membrane-bound organelle containing enzymes for digesting macromolecules and recycling cellular components.
|
Unit 2 |
| hydrolytic enzyme | [ /hˌaɪdrəlˈɪtɪk ˈɛnˌzaɪm/ ] | 水解酶 |
A class of digestive enzymes (such as acid hydrolases in lysosomes) that catalyze the cleavage of chemical bonds by the addition of water molecules.
|
Unit 2 |
| apoptosis | [ /ˌæpɔpˈtoʊsɪz/ ] | 细胞凋亡 |
Programmed cell death, a controlled process that eliminates unnecessary or damaged cells.
|
Unit 2 |
| vacuole | [ /ˈvækjuːoʊl/ ] | 液泡 |
A membrane-bound sac used for storage, waste disposal, and maintaining cell pressure.
|
Unit 2 |
| central vacuole | [ /ˈsɛntrəl ˈvækjuːoʊl/ ] | 中央大液泡 |
A large vacuole in plant cells that stores water and maintains turgor pressure.
|
Unit 2 |
| mitochondrion / mitochondria | [ /ˌmaɪtəˈkɑːndriən / ˌmaɪtəˈkɑːndriə/ ] | 线粒体 |
The organelle where cellular respiration occurs, producing ATP.
|
Unit 2 |
| cellular respiration | [ /ˈsɛljələr ˌrɛspərˈeɪʃən/ ] | 细胞呼吸 |
A process that converts glucose into ATP by breaking down organic molecules in the presence of oxygen.
|
Unit 2 |
| crista / cristae | [ /ˈkrɪstə / ˈkrɪstiː/ ] | 线粒体嵴 |
Infoldings of the inner mitochondrial membrane that house the electron transport chain and ATP synthase complexes, greatly increasing the surface area for ATP production.
|
Unit 2 |
| mitochondrial matrix | [ /mˌaɪtəkˈɑːndriːəl ˈmeɪtrɪks/ ] | 线粒体基质 |
The fluid-filled compartment enclosed by the inner mitochondrial membrane containing enzymes for the citric acid cycle, mitochondrial DNA, and ribosomes.
|
Unit 2 |
| intermembrane space | [ /ˌɪntərmbˈɛrən speɪs/ ] | 膜间隙 |
The narrow region between the inner and outer membranes of mitochondria or chloroplasts; serves as a reservoir for accumulated protons during chemiosmosis.
|
Unit 2 |
| chloroplast | [ /ˈklɔːrəplæst/ ] | 叶绿体 |
The organelle in plant and algal cells where photosynthesis occurs.
|
Unit 2 |
| photosynthesis | [ /ˌfoʊtoʊˈsɪnθəsɪs/ ] | 光合作用 |
The process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose.
|
Unit 2 |
| stroma | [ /ˈstroʊmə/ ] | 叶绿体基质 |
The dense fluid within the chloroplast surrounding the thylakoid membranes; site of the Calvin cycle (carbon fixation) and containing chloroplast DNA and ribosomes.
|
Unit 2 |
| thylakoid | [ /ˈθaɪləkɔɪd/ ] | 类囊体 |
A flattened, membranous sac inside a chloroplast arranged in stacks (grana); its membranes contain chlorophyll and pigments where light-dependent reactions occur.
|
Unit 2 |
| granum / grana | [ /ˈgrænəm / ˈgrænə/ ] | 基粒 |
A stack of membrane-bound thylakoid discs in chloroplasts where light absorption and photophosphorylation take place.
|
Unit 2 |
| endosymbiosis hypothesis | [ /ˌɛndoʊsˌaɪəmbˈiːəsəs haɪˈpɑθəsəs/ ] | 内共生假说 |
The theory that mitochondria and chloroplasts originated from free-living prokaryotes engulfed by ancestral eukaryotic cells.
|
Unit 2 |
| cytoskeleton | [ /sˌaɪtoʊksˈɛlətən/ ] | 细胞骨架 |
A network of protein fibers that provide structural support and enable cell movement.
|
Unit 2 |
| microtubule | [ /ˈmaɪˌkroʊˈtubjul/ ] | 微管 |
A cylinder-shaped component of the cytoskeleton involved in maintaining cell shape, transport, and division.
|
Unit 2 |
| microfilament | [ /mˌaɪkroʊfˈiːlməntənt/ ] | 微丝 |
A thin solid helical rod composed of actin protein monomers, forming part of the cytoskeleton and essential for cell motility, muscle contraction, and cytoplasmic streaming.
|
Unit 2 |
| cilium / cilia | [ /tʃˈɪliːəm / sˈɪliːə/ ] | 纤毛 |
Short, hair-like structures that move fluid or substances across a cell surface or propel the cell.
|
Unit 2 |
| flagellum / flagella | [ /fləˈʤɛləm / fləˈʤɛlə/ ] | 鞭毛 |
Long, whip-like structures that enable cell movement.
|
Unit 2 |
| centrosome | [ /ˈsɛntrəsoʊm/ ] | 中心体 |
The microtubule-organizing center of a cell, important in cell division.
|
Unit 2 |
| centriole | [ /ˈsɛntrioʊl/ ] | 中心粒 |
A cylinder composed of nine triplets of microtubules located in the centrosome of animal cells; involved in organizing the mitotic spindle during cell division.
|
Unit 2 |
| cell wall | [ /sɛl wɔl/ ] | 细胞壁 |
A rigid structure surrounding the plasma membrane in plant, fungal, and some prokaryotic cells, providing support and protection.
|
Unit 2 |
| cellulose | [ /ˈsɛljʊloʊs/ ] | 纤维素 |
A structural polysaccharide of plant cell walls consisting of straight, unbranched beta-1,4-linked glucose chains bundled into rigid, insoluble microfibrils.
|
Unit 2 |
| plasmodesma / plasmodesmata | [ /plˌæsmədˈoʊsmə / plˌæsməstˈɑːdəm/ ] | 胞间连丝 |
Open channels through the cell walls of adjacent plant cells connecting their cytoplasms and enabling intercellular transport and communication.
|
Unit 2 |
| second law of thermodynamics | [ /ˈsɛkənd lɔ əv θˌɜːrmədˈiːniːəsk/ ] | 热力学第二定律 |
Energy transformations increase the entropy （disorder） of the universe, and some energy is always lost as heat.
|
Unit 3 |
| entropy | [ /ˈɛntrəpi/ ] | 熵 |
A thermodynamic measure of the disorder, randomness, or thermal energy unavailable for doing mechanical work in a closed system; tends to increase spontaneously.
|
Unit 3 |
| Gibbs free energy (G) | [ /gɪbz fri ˈɛnərʤi/ ] | 吉布斯自由能 |
The portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system; a negative change in Gibbs free energy (ΔG < 0) indicates a spontaneous exergonic process.
|
Unit 3 |
| endergonic reaction | [ /ˌɛndərɡˈɑːnɪk riˈækʃən/ ] | 吸能反应 |
A chemical reaction that requires an input of energy, with products having more energy than reactants.
|
Unit 3 |
| exergonic reaction | [ /ˌɛɡzrˈɔːdʒɪnæk riˈækʃən/ ] | 放能反应 |
A chemical reaction that releases energy, with products having less energy than reactants.
|
Unit 3 |
| activation energy | [ /ˌæktəˈveɪʃən ˈɛnərʤi/ ] | 活化能 |
The minimum energy required to initiate a chemical reaction.
|
Unit 3 |
| active site | [ /ˈæktɪv saɪt/ ] | 活性位点 |
The region of an enzyme where substrates bind and the chemical reaction occurs.
|
Unit 3 |
| enzyme | [ /ˈɛnˌzaɪm/ ] | 酶 |
A biological catalyst that speeds up chemical reactions by lowering the activation energy.
|
Unit 3 |
| substrate | [ /ˈsʌbstreɪt/ ] | 底物 |
The specific reactant molecule upon which an enzyme acts and binds at its active site to undergo a catalyzed chemical transformation.
|
Unit 3 |
| optimal temperature | [ /ˈɑptɪməl ˈtɛmpərəʧər/ ] | 最适温度 |
The specific temperature at which an enzyme's catalytic activity is maximal; deviations above this point can cause thermal denaturation.
|
Unit 3 |
| optimal pH | [ /ˈɑptɪməl ˈpiˈeɪʧ/ ] | 最适pH |
The specific pH value at which an enzyme exhibits its maximum reaction velocity; changes in pH alter amino acid ionization at the active site.
|
Unit 3 |
| allosteric site | [ /ˌæləˈstɛrɪk saɪt/ ] | 别构位点 / 变构位点 |
A site on an enzyme, separate from the active site, where molecules can bind to regulate enzyme activity.
|
Unit 3 |
| noncompetitive inhibition | [ /ˌnɑnkəmˈpɛtətɪv ˌɪnəˈbɪʃən/ ] | 非竞争性抑制 |
Inhibition where a molecule binds to an allosteric site, reducing enzyme activity without competing with the substrate.
|
Unit 3 |
| inhibitor | [ /ˌɪnˈhɪbətər/ ] | 抑制剂 |
A substance that reduces or stops the catalytic activity of an enzyme, acting either competitively at the active site or noncompetitively at an allosteric site.
|
Unit 3 |
| competitive inhibition | [ /kəmˈpɛtɪtɪv ˌɪnəˈbɪʃən/ ] | 竞争性抑制 |
Inhibition where a molecule competes with the substrate for binding to the active site of an enzyme.
|
Unit 3 |
| coenzyme | [ /koʊˈɛnzaɪm/ ] | 辅酶 |
An organic molecule that assists enzymes in catalyzing reactions, often by transferring electrons or functional groups.
|
Unit 3 |
| adenosine triphosphate (ATP) | [ /əˈdɛnəsiːn traɪˈfɑːsfeɪt/ ] | 三磷酸腺苷 |
The primary energy carrier in cells, providing energy for various cellular processes.
|
Unit 3 |
| adenosine diphosphate (ADP) | [ /əˈdɛnəsiːn daɪˈfɑːsfeɪt/ ] | 二磷酸腺苷 |
A lower-energy molecule formed when ATP releases energy by losing a phosphate group.
|
Unit 3 |
| NAD+ / NADH | [ /næd / nˈæd/ ] | 烟酰胺腺嘌呤二核苷酸 |
Nicotinamide adenine dinucleotide; a coenzyme that functions as an electron carrier, alternating between its oxidized (NAD+) and reduced (NADH) states during metabolism.
|
Unit 3 |
| cellular respiration | [ /ˈsɛljələr ˌrɛspərˈeɪʃən/ ] | 细胞呼吸 |
A process that converts glucose into ATP by breaking down organic molecules in the presence of oxygen.
|
Unit 3 |
| electron carrier | [ /ˌɪˈlɛktrɑn ˈkɛriər/ ] | 电子载体 |
A molecule, such as NADH or FADH2, that transports high-energy electrons during cellular respiration or photosynthesis.
|
Unit 3 |
| FAD / FADH2 | [ /fæd / fˈæd/ ] | 黄素腺嘌呤二核苷酸 |
Flavin adenine dinucleotide; a redox-active electron carrier that accepts two electrons and two protons to form FADH2 during the citric acid cycle.
|
Unit 3 |
| glycolysis | [ /ɡlaɪˈkɑːləsɪs/ ] | 糖酵解 |
The first step of cellular respiration, where glucose is broken down into pyruvate， yielding ATP and NADH.
|
Unit 3 |
| pyruvate / pyruvic acid | [ /paɪˈruːveɪt / pɪrˈuːvɪk ˈæsəd/ ] | 丙酮酸 |
A three-carbon organic acid that is the end product of glycolysis and the starting substrate for the link reaction (pyruvate oxidation) in aerobic respiration or fermentation.
|
Unit 3 |
| pyruvate oxidation | [ /paɪˈruːveɪt ˌɑksəˈdeɪʃən/ ] | 丙酮酸氧化 |
The process of converting pyruvate into acetyl-CoA, producing NADH and releasing carbon dioxide.
|
Unit 3 |
| coenzyme A | [ /koʊˈɛnzaɪm ə/ ] | 辅酶A |
A vital sulfur-containing coenzyme derived from pantothenic acid (vitamin B5) that accepts acetyl groups from pyruvate to form acetyl-CoA, fueling the citric acid cycle.
|
Unit 3 |
| acetyl-CoA | [ /əsˌiːktoʊlˈiːkə/ ] | 乙酰辅酶A |
The two-carbon acetyl group attached to coenzyme A; forms when pyruvate is oxidized and enters the citric acid cycle by combining with oxaloacetate.
|
Unit 3 |
| Krebs cycle | [ /krɛbz ˈsaɪkəl/ ] | 三羧酸循环 (克雷布斯循环) |
A series of enzymatic reactions that produce ATP, NADH, and FADH2 by oxidizing acetyl-CoA
|
Unit 3 |
| oxidative phosphorylation | [ /ˈɑːksədˌeɪtɪv fˌoʊsfərˈeɪʃənliː/ ] | 氧化磷酸化 |
The production of ATP using energy derived from the electron transport chain and chemiosmosis.
|
Unit 3 |
| citric acid cycle | [ /ˈsɪtrɪk ˈæsəd ˈsaɪkəl/ ] | 柠檬酸循环 |
A cyclic metabolic pathway of eight chemical reactions in the mitochondrial matrix that oxidizes acetyl-CoA into carbon dioxide, generating ATP/GTP, NADH, and FADH2.
|
Unit 3 |
| electron transport chain (ETC) | [ /ˌɪˈlɛktrɑn ˈtrænspɔrt ʧeɪn/ ] | 电子传递链 |
A series of protein complexes that transfer electrons, creating a proton gradient used for ATP synthesis.
|
Unit 3 |
| chemiosmosis | [ /ˌkɛmiɑːzˈmoʊsɪs/ ] | 化学渗透 |
The movement of protons across a membrane to drive ATP synthesis using ATP synthase.
|
Unit 3 |
| ATP synthase | [ /ˌeɪ.tiːˈpiː ˈsɪnθeɪs/ ] | ATP合成酶 |
An enzyme that synthesizes ATP by using the energy from a proton gradient across a membrane.
|
Unit 3 |
| fermentation | [ /ˌfərmənˈteɪʃən/ ] | 发酵 |
An anaerobic process that generates ATP by converting glucose into byproducts like ethanol or lactic acid.
|
Unit 3 |
| alcohol fermentation | [ /ˈælkəˌhɑl ˌfərmənˈteɪʃən/ ] | 酒精发酵 |
A type of fermentation where glucose is converted into ethanol, carbon dioxide， and ATP.
|
Unit 3 |
| ethanol | [ /ˈɛθəˌnɔl/ ] | 乙醇 / 酒精 |
A two-carbon alcohol (C2H5OH) produced from pyruvate by yeasts and bacteria during anaerobic alcohol fermentation, regenerating NAD+ from NADH.
|
Unit 3 |
| lactic acid fermentation | [ /ˈlæktɪk ˈæsəd ˌfərmənˈteɪʃən/ ] | 乳酸发酵 |
A type of fermentation where glucose is converted into lactic acid and ATP.
|
Unit 3 |
| photosynthesis | [ /ˌfoʊtoʊˈsɪnθəsɪs/ ] | 光合作用 |
The process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose.
|
Unit 3 |
| stoma / stomata | [ /ˈstoʊmə / ˈstoʊmətə/ ] | 气孔 |
Microscopic openings on plant leaf surfaces regulated by guard cells that permit exchange of carbon dioxide and oxygen and regulate water vapor loss.
|
Unit 3 |
| light-dependent reaction (light reaction) | [ /lˈaɪtədˌɛnpənt riˈækʃən/ ] | 光反应 |
The first stage of photosynthesis, where light energy is captured to produce ATP and NADPH.
|
Unit 3 |
| chlorophyll | [ /ˈklɔːrəfɪl/ ] | 叶绿素 |
A green photosynthetic pigment embedded in thylakoid membranes that absorbs blue and red wavelengths of light while reflecting green light.
|
Unit 3 |
| photosystem I (PSI) | [ /ˈfoʊtoʊˌsɪstəm aɪ/ ] | 光系统I |
A light-harvesting protein-pigment complex in the thylakoid membrane with a reaction-center chlorophyll a pair known as P700; transfers electrons to NADP+ reductase.
|
Unit 3 |
| photosystem II (PSII) | [ /ˈfoʊtoʊˌsɪstəm ˈiː/ ] | 光系统II |
The light-harvesting complex in thylakoid membranes with P680 chlorophyll a that absorbs photons, splits water (photolysis), and releases O2 to initiate electron transport.
|
Unit 3 |
| light-independent reaction (dark reaction) | [ /lˈaɪtɪndɪpəntənd riˈækʃən/ ] | 暗反应 |
The enzymatic reactions of photosynthesis (Calvin cycle) occurring in the stroma of chloroplasts that fix atmospheric CO2 into carbohydrate using ATP and NADPH generated by the light reactions.
|
Unit 3 |
| Calvin cycle | [ /ˈkælvɪn ˈsaɪkəl/ ] | 卡尔文循环 |
The second stage of photosynthesis, where ATP and NADPH are used to convert carbon dioxide into glucose.
|
Unit 3 |
| glyceraldehyde 3-phosphate (G3P) | [ /ɡlˈaɪsərˌeɪldˌeɪ -ˈfɑsfeɪt/ ] | 甘油醛-3-磷酸 |
A three-carbon carbohydrate that is the direct product of the Calvin cycle and a pivotal metabolic intermediate in glycolysis and glucose synthesis.
|
Unit 3 |
| carbon fixation | [ /ˈkɑrbən fɪkˈseɪʃən/ ] | 固碳作用 |
The initial incorporation of inorganic carbon from CO2 into an organic compound (such as RuBP by the enzyme Rubisco) during the first phase of the Calvin cycle.
|
Unit 3 |
| signal transduction | [ /ˈsɪgnəl trænzdˈʌkʃən/ ] | 信号传导 |
The process by which a cell converts an external signal into a functional response.
|
Unit 4 |
| signaling molecule | [ /ˈsɪgnəlɪŋ ˈmɑləˌkjul/ ] | 信号分子 |
A chemical that conveys information between cells, such as hormones or neurotransmitters.
|
Unit 4 |
| ligand | [ /ˈlɪgənd/ ] | 配体 |
A molecule that binds specifically to a receptor to trigger a cellular response.
|
Unit 4 |
| ligand-binding domain | [ /lˈaɪɡəndˌaɪnd doʊˈmeɪn/ ] | 配体结合结构域 |
The specific region or pocket on a receptor protein where a signaling molecule (ligand) binds with high structural and chemical specificity to trigger receptor activation.
|
Unit 4 |
| receptor | [ /riˈsɛptər/ ] | 受体 |
A protein that detects signaling molecules and initiates a cellular response.
|
Unit 4 |
| membrane-bound receptor | [ /mˌɛmbrəndˈænb riˈsɛptər/ ] | 膜结合受体 |
A receptor embedded in the cell membrane that interacts with extracellular ligands.
|
Unit 4 |
| membrane-binding domain | [ /mˈɛmbrəndˌaɪnɪŋ doʊˈmeɪn/ ] | 膜结合结构域 |
A specialized structural region of an intracellular protein that recognizes and binds specific lipid headgroups or transmembrane receptor tails.
|
Unit 4 |
| intracellular / cytoplasmic domain | [ /ɪntrˈɛsəljər / ˌsaɪtəˈplæzmɪk doʊˈmeɪn/ ] | 细胞内结构域 |
The region of a transmembrane receptor located on the cytoplasmic interior of the cell that transmits the external signal into downstream intracellular cascades upon ligand binding.
|
Unit 4 |
| G protein-coupled receptor (GPCR) | [ /ʤi prətˈɛŋkətəld riˈsɛptər/ ] | G蛋白偶联受体 |
A membrane receptor that activates G proteins when a ligand binds to it.
|
Unit 4 |
| ligand-gated channel | [ /lˈɪɡəntˌeɪdʒd ˈʧænəl/ ] | 配体门控通道蛋白 |
A protein chanel that opens or closes in response to the binding of a ligand， allowing ions to pass.
|
Unit 4 |
| cyclic AMP (cAMP) | [ /ˈsaɪklɪk æmp/ ] | 环腺苷酸 (cAMP) |
Cyclic adenosine monophosphate; a key second messenger produced from ATP by adenylyl cyclase that activates protein kinase A (PKA) in cell signaling cascades.
|
Unit 4 |
| second messenger | [ /ˈsɛkənd ˈmɛsɪnʤər/ ] | 第二信使 |
A small molecule, such as cAMP or calcium, that relays a signal inside a cell after receptor activation.
|
Unit 4 |
| phosphorylation cascade | [ /fˌoʊsfərˈeɪʃənliː kæˈskeɪd/ ] | 磷酸化级联反应 |
A series of protein phosphorylation events that amplify and propagate a cellular signal.
|
Unit 4 |
| phosphorylation | [ /fˌoʊsfərˈeɪʃənliː/ ] | 磷酸化 |
The enzymatic covalent attachment of a phosphate group (PO4^3-) to a molecule (such as a protein by a kinase or ADP to make ATP), often altering protein activity, conformation, or localization.
|
Unit 4 |
| kinase | [ /kˈɪnəs/ ] | 蛋白激酶 |
An enzyme that catalyzes the transfer of a phosphate group to a substrate.
|
Unit 4 |
| intracellular receptor | [ /ɪntrˈɛsəljər riˈsɛptər/ ] | 细胞内受体 |
A receptor located within the cell that binds to small or hydrophobic signaling molecules.
|
Unit 4 |
| feedback | [ /ˈfidˌbæk/ ] | 反馈调节 |
A regulatory mechanism in which the output of a process influences its own activity.
|
Unit 4 |
| negative feedback | [ /ˈnɛgətɪv ˈfidˌbæk/ ] | 负反馈 |
A mechanism that reduces the output of a process to maintain homeostasis.
|
Unit 4 |
| mitosis | [ /maɪˈtoʊsɪs/ ] | 有丝分裂 |
A process of nuclear division in which a single cell divides to produce two identical daughter cells.
|
Unit 4 |
| homeostasis | [ /ˌhoʊmioʊˈsteɪsɪs/ ] | 内稳态 / 动态平衡 |
The maintenance of a stable internal environment despite exteral changes.
|
Unit 4 |
| positive feedback | [ /ˈpɑzətɪv ˈfidˌbæk/ ] | 正反馈 |
A mechanism that amplifies the output of a process, driving it further in the same direction.
|
Unit 4 |
| parent cell (parental cell) | [ /ˈpɛrənt sɛl/ ] | 母细胞 |
The original cell that undergoes replication of its genetic material and division (by mitosis or meiosis) to produce daughter cells.
|
Unit 4 |
| daughter cell | [ /ˈdɔtər sɛl/ ] | 子细胞 |
A cell formed by the division of a parental cell; genetically identical following mitosis, or genetically unique and haploid following meiosis.
|
Unit 4 |
| asexual reproduction | [ /eɪˈsɛksjuəl ˌriprəˈdəkʃən/ ] | 无性生殖 |
The production of offspring without the involvement of gametes or genetic recombination.
|
Unit 4 |
| cell cycle | [ /sɛl ˈsaɪkəl/ ] | 细胞周期 |
The sequence of events in the life of a cell, including growth, DNA replication, and division.
|
Unit 4 |
| interphase | [ /ˈɪntərfˌeɪs/ ] | 分裂间期 |
The preparatory period in the eukaryotic cell cycle between successive mitotic divisions, encompassing G1, S, and G2 phases, where cell growth and DNA replication occur.
|
Unit 4 |
| mitotic phase (M phase) | [ /ˌmaɪˈtɔtɪk feɪz/ ] | 分裂期 (M期) |
The phase of the cell cycle that includes mitosis (nuclear division) and cytokinesis (cytoplasmic division), partitioning replicated chromosomes into two daughter cells.
|
Unit 4 |
| G1 phase (G1 stage) | [ /ˈdʒiː ˈwʌn feɪz/ ] | G1期 (DNA合成前期) |
The first gap phase of interphase in the cell cycle prior to DNA synthesis, characterized by intense cellular growth, protein synthesis, and organelle replication.
|
Unit 4 |
| G2 phase (G2 stage) | [ /ˈdʒiː ˈtuː feɪz/ ] | G2期 (DNA合成后期) |
The second gap phase of interphase following DNA replication, during which the cell completes preparation and synthesizes proteins required for mitosis.
|
Unit 4 |
| S phase (S stage) | [ /ˈɛs feɪz/ ] | S期 (DNA合成期) |
The synthesis subphase of interphase in the cell cycle during which genomic DNA is replicated and centrosomes duplicate in preparation for cell division.
|
Unit 4 |
| chromatid | [ /ˈkroʊmətɪd/ ] | 染色单体 |
One of the two identical copies of DNA in a duplicated chromosome.
|
Unit 4 |
| chromosome | [ /ˈkroʊməˌzoʊm/ ] | 染色体 |
A structure made of DNA and proteins in a compact form that carries genetic information in cells.
|
Unit 4 |
| chromatin | [ /ˈkroʊmətɪn/ ] | 染色质 |
The complex of DNA and proteins in a loose form that forms chromosomes within the nucleus.
|
Unit 4 |
| sister chromatid | [ /ˈsɪstər ˈkroʊmətɪd/ ] | 姐妹染色单体 |
Two identical chromatids connected at a centromere, resulting from DNA replication.
|
Unit 4 |
| centromere | [ /ˈsɛntrəmiːr/ ] | 着丝粒 |
The constricted, specialized DNA region of a duplicated chromosome where sister chromatids are held closest together and where the kinetochore forms.
|
Unit 4 |
| prophase | [ /prˈɑːfəs/ ] | 前期 |
The first stage of mitosis, during which chromatin condenses into visible chromosomes, nucleoli disappear, and the mitotic spindle begins to assemble.
|
Unit 4 |
| metaphase | [ /mˈɛtəfˌeɪz/ ] | 中期 |
The stage of mitosis in which all duplicated chromosomes are aligned along the spindle equator (metaphase plate) midway between spindle poles.
|
Unit 4 |
| anaphase | [ /ˈænəfˌeɪz/ ] | 后期 |
The stage of mitosis in which sister chromatids separate at their centromeres and are pulled by kinetochore microtubules toward opposite spindle poles.
|
Unit 4 |
| telophase | [ /tˈɛləfˌeɪz/ ] | 末期 |
The final stage of mitosis in which daughter nuclei form at the poles, nuclear envelopes reassemble, nucleoli reappear, and chromosomes begin to decondense.
|
Unit 4 |
| spindle fiber (microtubule) | [ /ˈspɪndəl ˈfaɪbər/ ] | 纺锤丝 / 纺锤体微管 |
Microtubule polymers that extend from the centrosomes to attach to kinetochores or interdigitate at the spindle equator, orchestrating chromosome movement during mitosis and meiosis.
|
Unit 4 |
| kinetochore | [ /kɪˈnɛtəkɔːr/ ] | 动粒 / 着丝点 |
A specialized disc-shaped multiprotein structure attached to the centromere of each sister chromatid that links chromatids to mitotic spindle microtubules.
|
Unit 4 |
| metaphase plate | [ /mˈɛtəfˌeɪz pleɪt/ ] | 中期板 |
An imaginary plane perpendicular to the spindle axis halfway between the two poles of a dividing cell along which chromosomes align during metaphase.
|
Unit 4 |
| equatorial plate (equator) | [ /ˌikwəˈtɔriəl pleɪt/ ] | 赤道板 |
An imaginary plane perpendicular to the spindle axis halfway between the two spindle poles where duplicated chromosomes align during metaphase.
|
Unit 4 |
| cytokinesis | [ /sˌaɪtəkˈiːnsənz/ ] | 胞质分裂 |
The division of the cytoplasm to form two separate daughter cells after mitosis.
|
Unit 4 |
| cell plate | [ /sɛl pleɪt/ ] | 细胞板 |
A structure that forms in plant cells during cytokinesis to divide the cell into two.
|
Unit 4 |
| cyclin-dependent kinase (CDK) | [ /sˈaɪkəldˌɪnspˌɛnt kˈɪnəs/ ] | 周期蛋白依赖性激酶 |
An enzyme that drives cell cycle progression when activated by cyclins.
|
Unit 4 |
| cyclin | [ /sˈɪklɪn/ ] | 细胞周期蛋白 |
A protein that regulates the cell cycle by activating cyclin-dependent kinases （CDKs）.
|
Unit 4 |
| checkpoint | [ /ˈʧɛkˌpɔɪnt/ ] | 细胞周期检查点 |
A control point in the cell cycle where progression is halted until conditions are met.
|
Unit 4 |
| G1 checkpoint | [ /ʤi ˈʧɛkˌpɔɪnt/ ] | G1检查点 |
The primary control point (restriction point) in the cell cycle at the G1/S transition that assesses cell size, nutrient availability, growth factor signals, and DNA integrity before committing to replication.
|
Unit 4 |
| G2 checkpoint | [ /ʤi ˈʧɛkˌpɔɪnt/ ] | G2检查点 |
The regulatory checkpoint occurring at the G2/M transition that verifies successful and complete DNA replication and checks for DNA damage before permitting mitotic division.
|
Unit 4 |
| M checkpoint | [ /ɛm ˈʧɛkˌpɔɪnt/ ] | M检查点 |
The spindle assembly checkpoint (SAC) during metaphase that ensures all sister chromatids are correctly attached to spindle microtubules via kinetochores before initiating anaphase.
|
Unit 4 |
| G0 phase (G0 stage) | [ /ˈdʒiː ˈzɪroʊ feɪz/ ] | G0期 (休眠期/静止期) |
A non-dividing, quiescent state in which cells exit the cell cycle and perform differentiated physiological functions; can be temporary or permanent.
|
Unit 4 |
| cancer | [ /ˈkænsər/ ] | 癌症 / 恶性肿瘤 |
A disease characterized by uncontrolled cell division due to failures in cell cycle regulation.
|
Unit 4 |
| haploid (n) | [ /ˈhæplɔɪd/ ] | 单倍体 |
A cell containing one complete set of chromosomes, typical of gametes.
|
Unit 5 |
| diploid (2n) | [ /ˈdɪplɔɪd/ ] | 二倍体 |
A cell containing two complete sets of chromosomes, one from each parent.
|
Unit 5 |
| homologous chromosome | [ /hɑˈmɑləgəs ˈkroʊməˌzoʊm/ ] | 同源染色体 |
A pair of chromosomes, one from each parent, that are similar in shape, size, and gene content.
|
Unit 5 |
| autosome | [ /ˈɔːtoʊsˌoʊm/ ] | 常染色体 |
Any chromosome that is not a sex chromosome.
|
Unit 5 |
| sex chromosome | [ /sɛks ˈkroʊməˌzoʊm/ ] | 性染色体 |
A chromosome involved in determining the sex of an organism, such as X and Y in humans.
|
Unit 5 |
| sexual reproduction | [ /ˈsɛkʃuəl ˌriprəˈdəkʃən/ ] | 有性生殖 |
A mode of reproduction involving the fusion of gametes from two parents, resulting in offspring with genetic diversity.
|
Unit 5 |
| gamete | [ /ˈɡæmiːt/ ] | 配子 |
A mature haploid male or female reproductive cell (sperm or egg) capable of fusing with a gamete of the opposite sex during fertilization to form a diploid zygote.
|
Unit 5 |
| sperm | [ /spərm/ ] | 精子 |
The small, motile male gamete produced through spermatogenesis, delivering paternal genetic material to the ovum during fertilization.
|
Unit 5 |
| egg | [ /ɛg/ ] | 卵细胞 / 卵子 |
The non-motile, nutrient-dense female haploid gamete that fuses with a flagellated male sperm during fertilization to form a diploid zygote.
|
Unit 5 |
| fertilization | [ /ˌfərtəlɪˈzeɪʃən/ ] | 受精作用 |
The fusion of an egg and sperm cell to form a zygote.
|
Unit 5 |
| zygote | [ /ˈzaɪɡoʊt/ ] | 合子 / 受精卵 |
The diploid cell resulting from the fusion of male and female haploid gametes during fertilization, representing the initial cell of a new multicellular organism.
|
Unit 5 |
| meiosis | [ /maɪˈoʊsɪs/ ] | 减数分裂 |
A type of cell division that reduces chromosome number by half, producing haploid gametes.
|
Unit 5 |
| meiosis I | [ /maɪˈoʊsɪs aɪ/ ] | 减数第一次分裂 |
The first meiotic division (reduction division) in which homologous chromosome pairs synapse, undergo crossing over, and separate into two haploid daughter cells.
|
Unit 5 |
| meiosis II | [ /maɪˈoʊsɪs ˈiː/ ] | 减数第二次分裂 |
The second meiotic division (equational division) in which sister chromatids of duplicated haploid chromosomes separate, producing four genetically distinct haploid gametes.
|
Unit 5 |
| crossing over | [ /ˈkrɔsɪŋ ˈoʊvər/ ] | 交叉互换 |
The exchange of genetic material between homologous chromosomes during meiosis, increasing genetic diversity.
|
Unit 5 |
| random assortment of chromosomes | [ /ˈrændəm əˈsɔrtmənt əv ˈkroʊməˌzoʊmz/ ] | 染色体随机独立分配 |
The independent segregation of chromosomes during meiosis, contributing to genetic variation.
|
Unit 5 |
| Mendelian genetics | [ /mɛndˈɛljən ʤəˈnɛtɪks/ ] | 孟德尔遗传学 |
The fundamental principles of biological heredity formulated by Gregor Mendel, established by the law of segregation and the law of independent assortment of distinct particulate alleles.
|
Unit 5 |
| genetic variation | [ /ʤəˈnɛtɪk ˌvɛriˈeɪʃən/ ] | 遗传多样性 / 基因变异 |
Differences in DNA sequences among individuals within a population.
|
Unit 5 |
| true-breeding | [ /trˈuːbrˌiːɪŋ/ ] | 纯种 / 纯育品系 |
Referring to organisms that produce offspring of the same phenotypic variety when they self-pollinate or interbreed with another true-breeding organism of the same strain (homozygous).
|
Unit 5 |
| cross / hybridization | [ /krɔs / ˌhaɪbrɪdaɪˈzeɪʃən/ ] | 杂交 |
The controlled mating or breeding of two genetically distinct individuals to observe phenotypic ratios and inheritance patterns in offspring.
|
Unit 5 |
| trait | [ /treɪt/ ] | 性状 |
One of two or more detectable variants in an identifiable heritable phenotypic character (such as purple versus white flower color).
|
Unit 5 |
| character | [ /ˈkɛrɪktər/ ] | 特征 |
A heritable feature that varies among individuals in a population, such as flower color or eye color.
|
Unit 5 |
| monohybrid cross | [ /mənˈɑːfɪbriːd krɔs/ ] | 单因子杂交 |
A genetic cross between two individuals focusing on a single trait.
|
Unit 5 |
| P generation (parental generation) | [ /pi ˌʤɛnərˈeɪʃən/ ] | 亲代 (P代) |
The true-breeding (homozygous) initial parental generation in a Mendelian breeding experiment whose offspring form the F1 generation.
|
Unit 5 |
| F1 generation | [ /ɛf ˌʤɛnərˈeɪʃən/ ] | 子一代 (F1代) |
The first filial generation of hybrid offspring resulting from an experimental genetic cross between distinct parental (P generation) individuals.
|
Unit 5 |
| F2 generation | [ /ɛf ˌʤɛnərˈeɪʃən/ ] | 子二代 (F2代) |
The second filial generation produced by interbreeding or self-pollination among individuals of the F1 generation.
|
Unit 5 |
| Punnett square | [ /pˈʌnɪt skwɛr/ ] | 棋盘格 / 庞氏表 |
A visual checkerboard diagram used in genetics to predict the genotype and phenotype ratios resulting from a particular cross.
|
Unit 5 |
| complete dominance | [ /kəmˈplit ˈdɑmənəns/ ] | 完全显性 |
A pattern of inheritance in which one allele completely masks the effect of another allele.
|
Unit 5 |
| dominant | [ /ˈdɑmənənt/ ] | 显性的 |
An allele that expresses its phenotype even in the presence of a different allele.
|
Unit 5 |
| recessive | [ /rəˈsɛsɪv/ ] | 隐性的 |
An allele whose phenotype is masked in the presence of a dominant allele.
|
Unit 5 |
| monohybrid test cross | [ /mənˈɑːfɪbriːd tɛst krɔs/ ] | 单因子测交 |
A cross between an individual showing the dominant phenotype (of unknown genotype) and a homozygous recessive individual for a single trait.
|
Unit 5 |
| law of segregation | [ /lɔ əv ˌsɛgrəˈgeɪʃən/ ] | 分离定律 |
Mendel's principle stating that two alleles for a trait separate during gamete formation.
|
Unit 5 |
| phenotype | [ /ˈfiːnətaɪp/ ] | 表型 |
The observable physical or physiological traits of an organism.
|
Unit 5 |
| genotype | [ /ˈdʒiːnətaɪp/ ] | 基因型 |
The genetic makeup of an organism, represented by its alleles.
|
Unit 5 |
| homozygote / homozygous | [ /ˌhoʊmoʊˈzaɪgoʊt / ˌhoʊməˈzaɪɡəs/ ] | 纯合子 / 纯合的 |
An individual with two identical alleles for a specific gene.
|
Unit 5 |
| heterozygote / heterozygous | [ /hˌɛtərəsˈaɪtədʒ / ˌhɛtərəˈzaɪɡəs/ ] | 杂合子 / 杂合的 |
An individual with two different alleles for a specific gene.
|
Unit 5 |
| allele | [ /əˈliːl/ ] | 等位基因 |
A variant form of a gene at a particular locus on a chromosome.
|
Unit 5 |
| locus / loci | [ /ˈloʊkəs / ˈloʊki/ ] | 基因座 / 位点 |
The specific physical location or position of a gene on a chromosome.
|
Unit 5 |
| dihybrid cross | [ /dˈaɪəbrˌɪdə krɔs/ ] | 双因子杂交 |
A genetic cross between two individuals focusing on two traits.
|
Unit 5 |
| law of independent assortment | [ /lɔ əv ˌɪndɪˈpɛndənt əˈsɔrtmənt/ ] | 自由组合定律 |
Mendel's principle stating that genes for different traits segregate independently during gamete formation.
|
Unit 5 |
| dihybrid test cross | [ /dˈaɪəbrˌɪdə tɛst krɔs/ ] | 双因子测交 |
A cross between an individual heterozygous for two distinct genes (AaBb) and a homozygous double recessive individual (aabb) to test for genetic linkage.
|
Unit 5 |
| addition rule | [ /əˈdɪʃən rul/ ] | 加法法则 |
A probability rule stating that the probability of occurrence of any one of two or more mutually exclusive events is calculated by adding their individual probabilities.
|
Unit 5 |
| non-Mendelian genetics | [ /nˌɑːnmɛndˈɛliːən ʤəˈnɛtɪks/ ] | 非孟德尔遗传 |
Inheritance patterns that depart from simple Mendelian dominant/recessive ratios, including codominance, incomplete dominance, multiple alleles, sex linkage, and polygenic traits.
|
Unit 5 |
| multiplication rule | [ /ˌməltəpləˈkeɪʃən rul/ ] | 乘法法则 |
A probability rule stating that the joint probability of two or more independent events occurring simultaneously is the product of their individual probabilities.
|
Unit 5 |
| incomplete dominance | [ /ˌɪnkəmˈplit ˈdɑmənəns/ ] | 不完全显性 |
A pattern of inheritance where the phenotype of heterozygotes is an intermediate blend of both alleles.
|
Unit 5 |
| pleiotropy | [ /plaɪˈɑːtrəpi/ ] | 一因多效 / 基因多效性 |
A single gene affecting multiple traits in an organism.
|
Unit 5 |
| codominance | [ /koʊˈdɑːmɪnəns/ ] | 共显性 |
A pattern of inheritance where both alleles in a heterozygote are fully expressed.
|
Unit 5 |
| multiple alleles | [ /ˈməltəpəl əˈliːlz/ ] | 复等位基因 |
More than two forms of a gene that can occupy a single locus.
|
Unit 5 |
| non-nuclear inheritance | [ /ˈnɑˈnuˌkliər ˌɪnˈhɛrətəns/ ] | 非核遗传 / 细胞质遗传 |
Inheritance of genetic material not found in the nucleus, such as mitochondrial DNA.
|
Unit 5 |
| epistasis | [ /ɛˈpɪstəsɪs/ ] | 上位效应 / 基因上位性 |
A genetic interaction where one gene masks or modifies the effect of another gene.
|
Unit 5 |
| polygenic inheritance | [ /pˌɑːliːɡˈɛnɪk ˌɪnˈhɛrətəns/ ] | 多基因遗传 |
An additive genetic effect of two or more independent genes determining a single phenotypic characteristic, resulting in continuous quantitative variation (e.g., human height and skin pigmentation).
|
Unit 5 |
| sex-linked trait | [ /sˈɛkslˌaɪknd treɪt/ ] | 伴性性状 |
A phenotypic trait determined by an allele situated on a sex chromosome (typically the X chromosome in humans), exhibiting characteristic sex-skewed inheritance frequencies.
|
Unit 5 |
| sex-linked gene | [ /sˈɛkslˌaɪknd ʤin/ ] | 伴性基因 |
A gene located on a sex chromosome, often showing different patterns of inheritance in males and females.
|
Unit 5 |
| X chromosome | [ /ɛks ˈkroʊməˌzoʊm/ ] | X染色体 |
The larger of the two mammalian sex chromosomes; females carry two copies (XX) while males carry one copy (XY), encoding thousands of genes vital for both sexes.
|
Unit 5 |
| Y chromosome | [ /waɪ ˈkroʊməˌzoʊm/ ] | Y染色体 |
The smaller mammalian sex chromosome that contains the SRY (sex-determining region Y) master gene responsible for triggering male testicular development in XY embryos.
|
Unit 5 |
| linked genes | [ /lɪŋkt ʤinz/ ] | 连锁基因 |
Genes located close together on the same chromosome that tend to be inherited together.
|
Unit 5 |
| parental phenotype | [ /pərˈɛntəl ˈfiːnətaɪp/ ] | 亲本表型 |
An offspring phenotype that precisely matches one of the original homozygous or heterozygous parental phenotypes involved in the cross, without recombination.
|
Unit 5 |
| pedigree | [ /ˈpɛdəgri/ ] | 系谱图 / 家族遗传系谱 |
A chart representing family relationships and inheritance patterns of traits.
|
Unit 5 |
| recombinant phenotype | [ /rɪˈkɑmbɪnənt ˈfiːnətaɪp/ ] | 重组表型 |
An offspring phenotype that exhibits a novel combination of traits differing from both parents, resulting from crossing over during meiosis or independent assortment.
|
Unit 5 |
| linkage map | [ /ˈlɪŋkɪʤ mæp/ ] | 连锁图谱 / 基因图谱 |
A genetic map depicting the relative locations of genes along a chromosome based on the frequency of meiotic crossing over (recombination frequency).
|
Unit 5 |
| autosomal dominant trait | [ /ˌɔːtəsˈoʊməl ˈdɑmənənt treɪt/ ] | 常染色体显性遗传性状 |
A phenotypic condition or trait caused by a dominant allele located on an autosome (non-sex chromosome), requiring only a single copy of the allele for phenotypic expression.
|
Unit 5 |
| autosomal recessive trait | [ /ˌɔːtəsˈoʊməl rəˈsɛsɪv treɪt/ ] | 常染色体隐性遗传性状 |
A phenotypic condition or trait caused by a recessive allele on an autosome, expressed exclusively in homozygous individuals who inherit mutant alleles from both parents.
|
Unit 5 |
| X-linked dominant trait | [ /zˈɪlksɪnkəd ˈdɑmənənt treɪt/ ] | X连锁显性遗传性状 |
A mode of genetic inheritance where a dominant mutation on the X chromosome causes the phenotype; affected males transmit the condition to all daughters but no sons.
|
Unit 5 |
| X-linked recessive trait | [ /zˈɪlksɪnkəd rəˈsɛsɪv treɪt/ ] | X连锁隐性遗传性状 |
A mode of inheritance caused by a recessive mutation on the X chromosome, expressing much more frequently in hemizygous males (XY) than in females (XX).
|
Unit 5 |
| Y-linked trait | [ /jˈɪlŋktɪd treɪt/ ] | Y连锁遗传性状 |
A phenotypic trait determined exclusively by genes on the Y chromosome (holandric), transmitted strictly and directly from father to all biological sons.
|
Unit 5 |
| maternal inheritance | [ /məˈtərnəl ˌɪnˈhɛrətəns/ ] | 母系遗传 |
The transmission of genetic material exclusively from the mother, often via mitochondria.
|
Unit 5 |
| carrier | [ /ˈkɛriər/ ] | 致病基因携带者 |
An individual who has one copy of a recessive allele but does not exhibit the associated phenotype.
|
Unit 5 |
| transformation experiment | [ /ˌtrænsfərˈmeɪʃən ɪkˈspɛrəmənt/ ] | 转化实验 |
A landmark 1928 experiment by Frederick Griffith (and later refined in 1944 by Avery, MacLeod, and McCarty) demonstrating that genetic material can be transferred between bacterial cells, identifying DNA as the transforming principle.
|
Unit 6 |
| transforming principle | [ /trænsˈfɔrmɪŋ ˈprɪnsəpəl/ ] | 转化因子 |
The early biochemical term for the substance (identified by Avery, MacLeod, and McCarty as DNA) responsible for transferring genetic information between bacterial strains in Griffith's experiment.
|
Unit 6 |
| bacteriophage / phage | [ /bæktˌɪrjˈuːdʒˌæf / feɪʤ/ ] | 噬菌体 |
A virus that infects and replicates within bacteria.
|
Unit 6 |
| semiconservative model | [ /sˌɛmiːkənsərpˈæʃɪv ˈmɑdəl/ ] | 半保留复制模型 |
A model of DNA replication in which each new DNA molecule consists of one original strand and one newly synthesized strand.
|
Unit 6 |
| template strand / parental strand | [ /ˈtɛmplət strænd / pərˈɛntəl strænd/ ] | 模板链 / 母链 |
The specific strand of a double-stranded DNA molecule that serves as the guide for the synthesis of a complementary RNA during transcription or a new DNA strand during replication.
|
Unit 6 |
| DNA replication | [ /ˌdiː.ɛnˈeɪ ˌrɛplɪˈkeɪʃən/ ] | DNA复制 |
The process of copying a DNA molecule to produce two identical DNA strands.
|
Unit 6 |
| new strand / daughter strand | [ /nu strænd / ˈdɔtər strænd/ ] | 新合成链 / 子链 |
The newly synthesized complementary DNA strand formed during replication through phosphodiester bond synthesis catalyzed by DNA polymerase.
|
Unit 6 |
| origin of replication | [ /ˈɔrəʤən əv ˌrɛplɪˈkeɪʃən/ ] | 复制起始点 |
A specific nucleotide sequence along a chromosome where DNA replication begins and replication bubbles open.
|
Unit 6 |
| replication fork | [ /ˌrɛplɪˈkeɪʃən fɔrk/ ] | 复制叉 |
A Y-shaped region on a replicating DNA molecule where the parental double helix is unwound and new strands are continuously and discontinuously synthesized.
|
Unit 6 |
| helicase | [ /ˈhɛlɪkeɪs/ ] | 解旋酶 |
An enzyme that unwinds the DNA double helix by breaking hydrogen bonds between complementary bases.
|
Unit 6 |
| topoisomerase | [ /təpˈɔɪzmˌɑːrəs/ ] | 拓扑异构酶 |
An enzyme that prevents the overwinding or tangling of DNA during replication by cutting and rejoining DNA strands.
|
Unit 6 |
| primase | [ /priːmˈɑːsiː/ ] | 引物酶 |
An RNA polymerase enzyme that synthesizes short RNA primers (approx. 5-10 nucleotides) providing a 3'-OH group required for DNA polymerase initiation.
|
Unit 6 |
| primer | [ /ˈpraɪmər/ ] | RNA引物 |
A short RNA sequence that provides a starting point for DNA synthesis.
|
Unit 6 |
| DNA polymerase | [ /ˌdiː.ɛnˈeɪ pəˈlɪməreɪs/ ] | DNA聚合酶 |
An enzyme that synthesizes new DNA strands by adding nucleotides to a template strand
|
Unit 6 |
| leading strand | [ /ˈlidɪŋ strænd/ ] | 前导链 |
The DNA strand synthesized continuously in the 5' to 3' direction during replication.
|
Unit 6 |
| DNA ligase | [ /ˌdiː.ɛnˈeɪ ˈlaɪɡeɪs/ ] | DNA连接酶 |
An enzyme that joins DNA fragments by forming phosphodiester bonds.
|
Unit 6 |
| lagging strand | [ /ˈlægɪŋ strænd/ ] | 后随链 / 滞后链 |
The DNA strand synthesized discontinuously in short fragments, called Okazaki fragments, during replication.
|
Unit 6 |
| Okazaki fragment | [ /ˌoʊkəˈzɑːki ˈfræɡmənt/ ] | 冈崎片段 |
A series of short, discontinuously synthesized DNA segments on the lagging strand during DNA replication, subsequently joined by DNA ligase.
|
Unit 6 |
| naked DNA | [ /ˈneɪkəd ˈdiˌɛˈneɪ/ ] | 裸露DNA (无组蛋白包裹) |
DNA that is not packaged or wrapped around histone protein octamers, characteristic of prokaryotic nucleoids, circular bacterial plasmids, chloroplasts, and mitochondria.
|
Unit 6 |
| histone | [ /hˈɪstoʊn/ ] | 组蛋白 |
A small, highly basic protein rich in lysine and arginine that binds electrostatically to negatively charged DNA, assembling into octamers around which DNA winds to form nucleosomes.
|
Unit 6 |
| plasmid | [ /ˈplæzmɪd/ ] | 质粒 |
A small, circular piece of DNA found in bacteria, often used in genetic engineering.
|
Unit 6 |
| gene | [ /ʤin/ ] | 基因 |
A segment of DNA that encodes a functional product, usually a protein.
|
Unit 6 |
| gene expression | [ /ʤin ɪkˈsprɛʃən/ ] | 基因表达 |
The process by which information from a gene is used to synthesize RNA and proteins.
|
Unit 6 |
| central dogma | [ /ˈsɛntrəl ˈdɑgmə/ ] | 中心法则 |
The concept that genetic information flows from DNA to RNA to protein.
|
Unit 6 |
| transcription | [ /ˌtrænˈskrɪpʃən/ ] | 转录 |
The process of synthesizing RNA from a DNA template.
|
Unit 6 |
| translation | [ /trænzˈleɪʃən/ ] | 翻译 |
The process of synthesizing a protein from an mRNA template.
|
Unit 6 |
| promoter | [ /prəˈmoʊtər/ ] | 启动子 |
A DNA sequence that signals the start of transcription and is recognized by RNA polymerase.
|
Unit 6 |
| RNA polymerase | [ /ˌɑːr.ɛnˈeɪ pəˈlɪməreɪs/ ] | RNA聚合酶 |
An enzyme that synthesizes RNA by using a DNA template.
|
Unit 6 |
| transcription factor | [ /ˌtrænˈskrɪpʃən ˈfæktər/ ] | 转录因子 |
A protein that binds to DNA and regulates the transcription of genes.
|
Unit 6 |
| non-template strand | [ /nˈɔːntmpˌɔːltˌeɪ strænd/ ] | 非模板链 |
The strand of DNA that is not transcribed into RNA; possesses the identical base sequence to the resulting mRNA transcript (with T instead of U), also called coding strand.
|
Unit 6 |
| coding strand | [ /ˈkoʊdɪŋ strænd/ ] | 编码链 |
The DNA strand whose base sequence corresponds directly to the codon sequence of the mRNA transcript produced (with thymine in place of uracil).
|
Unit 6 |
| template strand | [ /ˈtɛmplət strænd/ ] | 模板链 |
The specific strand of a double-stranded DNA molecule that serves as the guide for the synthesis of a complementary RNA during transcription or a new DNA strand during replication.
|
Unit 6 |
| non-coding strand | [ /nˈɑːndˈoʊkɪŋ strænd/ ] | 非编码链 |
Alternative term for the template strand of DNA; serves as the template read by RNA polymerase in the 3' to 5' direction during transcription.
|
Unit 6 |
| messenger RNA (mRNA) | [ /ˈmɛsɪndʒər ˌɑːr.ɛnˈeɪ/ ] | 信使RNA |
RNA that carries genetic information from DNA to ribosomes for protein synthesis.
|
Unit 6 |
| pre-mRNA | [ /prˈɛmnrə/ ] | 前体信使RNA |
The initial RNA transcript produced during transcription, which requires processing before becoming mature mRNA
|
Unit 6 |
| RNA processing | [ /rˈeɪn ˈprɑsɛsɪŋ/ ] | RNA加工 / 转录后加工 |
The modification of pre-mRNA, including splicing, capping, and adding a poly-A tail, to produce mature mRNA.
|
Unit 6 |
| 5' cap (GTP cap) | [ /kæp/ ] | 5'端帽子 (GTP帽子) |
A specially altered guanine nucleotide (7-methylguanosine) added to the 5' end of eukaryotic pre-mRNA to prevent nucleolytic degradation and assist ribosome binding.
|
Unit 6 |
| poly-A tail | [ /pˈoʊliːə teɪl/ ] | 多聚腺苷酸尾 (poly-A尾) |
A stretch of 50 to 250 adenine nucleotides added enzymatically to the 3' end of pre-mRNA during eukaryotic mRNA processing to enhance stability and nuclear export.
|
Unit 6 |
| RNA splicing | [ /rˈeɪn ˈsplaɪsɪŋ/ ] | RNA剪接 |
The removal of introns and joining of exons in pre-mRNA to form mature mRNA
|
Unit 6 |
| alternative RNA splicing | [ /ɔlˈtərnətɪv rˈeɪn ˈsplaɪsɪŋ/ ] | 选择性剪接 |
A process that allows a single gene to produce multiple protein variants by splicing pre-mRNA in different ways.
|
Unit 6 |
| intron | [ /ˈɪntrɑːn/ ] | 内含子 |
A non-coding sequence of RNA that is removed during RNA splicing.
|
Unit 6 |
| exon | [ /ˈɛksɑːn/ ] | 外显子 |
A coding sequence of RNA that remains in mature mRNA after splicing
|
Unit 6 |
| genetic code | [ /ʤəˈnɛtɪk koʊd/ ] | 遗传密码 |
The set of rules by which nucleotide sequences in mRNA are translated into amino acids.
|
Unit 6 |
| start codon | [ /stɑrt kˈoʊdən/ ] | 起始密码子 |
The specific mRNA codon (typically 5'-AUG-3') that signals the ribosome to begin translation and codes for the first amino acid, methionine.
|
Unit 6 |
| codon | [ /kˈoʊdən/ ] | 密码子 |
A three-nucleotide sequence in mRNA that specifies a particular amino acid or stop signal during translation.
|
Unit 6 |
| stop codon | [ /stɑp kˈoʊdən/ ] | 终止密码子 |
One of three specific mRNA triplet codons (5'-UAA-3', 5'-UAG-3', 5'-UGA-3') that do not code for amino acids and signal the release factor to terminate translation.
|
Unit 6 |
| transfer RNA (tRNA) | [ /ˈtrænsfɜːr ˌɑːr.ɛnˈeɪ/ ] | 转运RNA |
RNA that carries amino acids to ribosomes and matches them to codons in mRNA during translation.
|
Unit 6 |
| anticodon | [ /ˌæntiːkˈɑːdən/ ] | 反密码子 |
A three-nucleotide sequence in tRNA that pairs with a complementary codon in mRNA.
|
Unit 6 |
| virus | [ /ˈvaɪrəs/ ] | 病毒 |
A small infectious agent composed of genetic material and a protein coat, capable of replicating only inside a host cell.
|
Unit 6 |
| DNA virus | [ /ˈdiˌɛˈneɪ ˈvaɪrəs/ ] | DNA病毒 |
A virus whose genetic genome consists of either single-stranded or double-stranded DNA, replicating via DNA-dependent DNA polymerases within host cells.
|
Unit 6 |
| RNA virus | [ /rˈeɪn ˈvaɪrəs/ ] | RNA病毒 |
A virus whose genome consists of RNA (positive-sense, negative-sense, or retroviral), replicating using RNA-dependent RNA polymerases or reverse transcriptase.
|
Unit 6 |
| capsid | [ /kˈæpst/ ] | 衣壳 / 病毒蛋白质外壳 |
The protective external protein shell of a virus that encloses and shields its viral genetic material (DNA or RNA) from degradation.
|
Unit 6 |
| retrovirus | [ /ˌrɛtroʊˈvaɪrəs/ ] | 逆转录病毒 |
A virus that uses reverse transcription to convert its RNA genome into DNA.
|
Unit 6 |
| reverse transcription | [ /rɪˈvərs ˌtrænˈskrɪpʃən/ ] | 逆转录 |
The process of synthesizing DNA from an RNA template.
|
Unit 6 |
| gene regulation | [ /ʤin ˌrɛgjəˈleɪʃən/ ] | 基因表达调控 |
The control of gene expression, ensuring that genes are expressed at the right times and levels.
|
Unit 6 |
| regulatory sequence | [ /ˈrɛgjələˌtɔri ˈsikwəns/ ] | 调控序列 |
A DNA sequence that influences gene expression by serving as a binding site for regulatory proteins.
|
Unit 6 |
| reverse transcriptase | [ /rɪˈvərs trænskrˈɪpstˌeɪts/ ] | 逆转录酶 |
An enzyme used by retroviruses to carry out reverse transcription.
|
Unit 6 |
| trp operon | [ /trˈɛptər ˈɑːpərɑːn/ ] | 色氨酸操纵子 |
A repressible bacterial operon in E. coli containing genes for tryptophan biosynthesis, repressed when tryptophan levels are high and binds to the Trp repressor.
|
Unit 6 |
| differentiation | [ /ˌdɪfərˌɛnʧiˈeɪʃən/ ] | 细胞分化 |
The biological developmental process by which unspecialized stem cells become structurally and functionally specialized through selective differential gene expression.
|
Unit 6 |
| operon | [ /ˈɑːpərɑːn/ ] | 操纵子 |
A cluster of genes under the control of a single promoter, typically found in prokaryotes.
|
Unit 6 |
| lac operon | [ /læk ˈɑːpərɑːn/ ] | 乳糖操纵子 |
An inducible bacterial operon in E. coli that encodes enzymes for lactose uptake and catabolism, activated in the presence of lactose (allolactose) and absence of glucose.
|
Unit 6 |
| operator | [ /ˈɑpərˌeɪtər/ ] | 操纵基因 / 操纵序列 |
A regulatory DNA sequence in a prokaryotic operon located within or near the promoter where an active repressor protein binds to block RNA polymerase transcription.
|
Unit 6 |
| regulatory gene | [ /ˈrɛgjələˌtɔri ʤin/ ] | 调控基因 |
A gene that codes for a protein (such as a repressor, activator, or transcription factor) that controls the transcription of other target genes or operons.
|
Unit 6 |
| histone acetylation | [ /hˈɪstoʊn ˌeɪsətəlˈeɪʃən/ ] | 组蛋白乙酰化 |
The addition of acetyl groups to histones, loosening chromatin structure and promoting gene expression.
|
Unit 6 |
| DNA methylation | [ /ˈdiˌɛˈneɪ mˌɛθliːˈeɪtənəl/ ] | DNA甲基化 |
The addition of methyl groups to DNA, typically suppressing gene expression.
|
Unit 6 |
| repressor | [ /rɪprˈɛsər/ ] | 阻遏蛋白 |
A protein that inhibits transcription by binding to a regulatory sequence.
|
Unit 6 |
| general transcription factor | [ /ˈʤɛnərəl ˌtrænˈskrɪpʃən ˈfæktər/ ] | 通用转录因子 |
An essential regulatory protein that binds directly to the promoter (such as the TATA box) or to RNA polymerase II, assembling the basal transcription pre-initiation complex.
|
Unit 6 |
| specific transcription factor | [ /spɪˈsɪfɪk ˌtrænˈskrɪpʃən ˈfæktər/ ] | 特异性转录因子 |
A regulatory protein (activator or repressor) that binds to distal enhancers or proximal elements to dramatically modulate the rate of transcription of specific target genes.
|
Unit 6 |
| enhancer | [ /ɛnˈhænsər/ ] | 增强子 |
A DNA sequence that increases the transcription of a gene when bound by activators.
|
Unit 6 |
| activator | [ /ˈæktəˌveɪtər/ ] | 激活蛋白 / 活化剂 |
A protein that increases gene expression by binding to regulatory sequences.
|
Unit 6 |
| mutation | [ /mjuˈteɪʃən/ ] | 基因突变 |
A change in the DNA sequence that can affect genetic information.
|
Unit 6 |
| point mutation | [ /pɔɪnt mjuˈteɪʃən/ ] | 点突变 |
A single nucleotide change in a DNA sequence.
|
Unit 6 |
| silent mutation | [ /ˈsaɪlənt mjuˈteɪʃən/ ] | 同义突变 / 沉默突变 |
A mutation that does not alter the amino acid sequence of a protein.
|
Unit 6 |
| substitution mutation | [ /ˌsəbstɪˈtuʃən mjuˈteɪʃən/ ] | 碱基替换突变 |
A type of point mutation where one nucleotide base pair in DNA is replaced by another, which can result in silent, missense, or nonsense codons.
|
Unit 6 |
| missense mutation | [ /mɪsˈɛns mjuˈteɪʃən/ ] | 错义突变 |
A mutation that results in a different amino acid being incorporated into a protein.
|
Unit 6 |
| nonsense mutation | [ /ˈnɑnsɛns mjuˈteɪʃən/ ] | 无义突变 |
A mutation that introduces a premature stop codon, terminating protein synthesis.
|
Unit 6 |
| insertion mutation | [ /ˌɪnˈsərʃən mjuˈteɪʃən/ ] | 插入突变 |
A genetic mutation involving the addition of one or more nucleotide base pairs into a DNA sequence, frequently causing catastrophic reading frameshifts if not a multiple of three.
|
Unit 6 |
| deletion mutation | [ /dɪˈliʃən mjuˈteɪʃən/ ] | 缺失突变 |
A genetic mutation involving the loss or excision of one or more nucleotide base pairs from a DNA sequence, altering the protein sequence or shifting the reading frame.
|
Unit 6 |
| frameshift mutation | [ /frˈeɪmʃˌɪft mjuˈteɪʃən/ ] | 移码突变 |
A mutation caused by insertions or deletions that shift the reading frame of a gene.
|
Unit 6 |
| sickle-cell anemia (sickle-cell disease) | [ /sˈɪksləs əˈnimiə/ ] | 镰刀型细胞贫血症 |
A severe hereditary hemoglobinopathy caused by a point mutation (missense: GAG -> GTG, encoding Val instead of Glu at position 6 of the beta-globin chain), causing red blood cells to deform into sickled shapes.
|
Unit 6 |
| duplication | [ /ˌdjupləˈkeɪʃən/ ] | 重复突变 / 染色体重复 |
A chromosomal mutation or DNA sequence alteration in which an entire segment of genetic material is replicated, producing tandem redundant copies.
|
Unit 6 |
| inversion | [ /ˌɪnˈvərʒən/ ] | 倒位突变 / 染色体倒位 |
A chromosomal structural alteration in which a segment breaks off, reverses its orientation by 180 degrees, and reattaches to the same chromosome.
|
Unit 6 |
| translocation | [ /trˌænzlɑːkˈeɪʃən/ ] | 易位突变 / 染色体易位 |
A chromosomal mutation involving the breakage and attachment of a chromosome segment to an entirely non-homologous chromosome.
|
Unit 6 |
| nondisjunction | [ /ˌnɑːndɪsˈdʒʌŋkʃən/ ] | 染色体不分离 |
The failure of chromosomes to separate properly during cell division.
|
Unit 6 |
| Down syndrome (Trisomy 21) | [ /daʊn ˈsɪndroʊm ˈtraɪsoʊmi ˈtwɛnti ˈwʌn/ ] | 唐氏综合征 (21三体综合征) |
A human chromosomal condition caused by the presence of an extra 21st chromosome (aneuploidy via nondisjunction), leading to developmental and intellectual variations.
|
Unit 6 |
| polyploidy | [ /ˈpɑːliˌplɔɪdi/ ] | 多倍体 |
A condition in which an organism has more than two complete sets of chromosomes.
|
Unit 6 |
| triploidy | [ /trˈɪplˌɔɪd/ ] | 三倍体 |
A chromosomal condition in which an organism possesses three complete sets of chromosomes (3n), resulting in reproductive sterility in animals.
|
Unit 6 |
| tetraploidy | [ /tˌɛtrəpˈɑːldiː/ ] | 四倍体 |
A polyploid condition in which an organism possesses four complete sets of chromosomes (4n), common in angiosperm plants and contributing to speciation.
|
Unit 6 |
| spontaneous mutation | [ /spɑnˈteɪniəs mjuˈteɪʃən/ ] | 自发突变 |
A genetic mutation that arises naturally inside cells from intrinsic biochemical errors during DNA replication, cellular oxidative stress, or spontaneous depurination/deamination.
|
Unit 6 |
| induced mutation | [ /ˌɪnˈdust mjuˈteɪʃən/ ] | 诱发突变 |
A genetic mutation produced deliberately or accidentally through exposure to external environmental mutagens, such as ionizing radiation, ultraviolet light, or reactive chemical mutagens.
|
Unit 6 |
| horizontal gene transfer (lateral gene transfer) | [ /ˌhɔrəˈzɑntəl ʤin ˈtrænsfər/ ] | 水平基因转移 |
The transmission of genetic material between distinct organisms across species or lineages without sexual reproduction, occurring via transformation, transduction, or conjugation.
|
Unit 6 |
| mutagen | [ /mˈjutəʤɛn/ ] | 诱变剂 |
An agent that induces genetic mutations.
|
Unit 6 |
| transformation | [ /ˌtrænsfərˈmeɪʃən/ ] | 转化作用 |
The uptake of foreign DNA by a cell from its surroundings.
|
Unit 6 |
| transduction | [ /trænzdˈʌkʃən/ ] | 转导作用 |
The transfer of genetic material between cells via a virus.
|
Unit 6 |
| conjugation | [ /ˌkɑnʤəˈgeɪʃən/ ] | 接合作用 |
The direct transfer of DNA between two bacterial cells through physical contact.
|
Unit 6 |
| transposition | [ /trˌænspəzˈɪʃən/ ] | 转座作用 |
The movement of DNA segments within a genome.
|
Unit 6 |
| polymerase chain reaction (PCR) | [ /pəˈlɪməreɪs ʧeɪn riˈækʃən/ ] | 聚合酶链式反应 |
A technique for amplifying DNA sequences in vitro.
|
Unit 6 |
| viral reassortment | [ /ˈvaɪrəl rˌiːəsˈɜːrmənt/ ] | 病毒基因重配 |
The exchange of genetic material between viruses infecting the same host, creating new viral strains.
|
Unit 6 |
| biotechnology | [ /ˌbaɪoʊˌtɛkˈnɑləʤi/ ] | 生物技术 |
The technological exploitation and manipulation of biological systems, living organisms, or genetic material to develop useful products and medical therapies.
|
Unit 6 |
| denaturation | [ /dɪnˈækjətrˈeɪʃən/ ] | DNA变性 (解链) |
A process in which a protein loses its native three-dimensional tertiary/secondary structure due to disruption of weak chemical bonds and interactions by heat, extreme pH, or chemical agents, rendering it biologically inactive.
|
Unit 6 |
| annealing | [ /əˈnilɪŋ/ ] | 引物退火 (复性) |
The phase in PCR (polymerase chain reaction) where the reaction temperature is lowered to allow short oligonucleotide primers to hybridize to target DNA strands.
|
Unit 6 |
| extension / elongation | [ /ɪkˈstɛnʃən / ˌilɔŋˈgeɪʃən/ ] | DNA延伸 |
The final stage of a PCR cycle in which Taq DNA polymerase synthesizes a complementary DNA strand by adding dNTPs to the 3' ends of primers at around 72°C.
|
Unit 6 |
| gel electrophoresis | [ /ʤɛl ˌɪˌlɛktroʊfɔˈrɪsɪs/ ] | 凝胶电泳 |
A method for separating DNA fragments based on size using an electric field.
|
Unit 6 |
| DNA sequencing | [ /ˈdiˌɛˈneɪ ˈsikwənsɪŋ/ ] | DNA测序 |
The process of determining the nucleotide sequence of a DNA molecule.
|
Unit 6 |
| genetic engineering | [ /ʤəˈnɛtɪk ˈɛnʤəˈnɪrɪŋ/ ] | 基因工程 |
The direct manipulation of an organism's DNA to alter its characteristics.
|
Unit 6 |
| restriction enzyme | [ /riˈstrɪkʃən ˈɛnˌzaɪm/ ] | 限制性核酸内切酶 |
An enzyme that cuts DNA at specific sequences.
|
Unit 6 |
| complementary DNA (cDNA) | [ /ˌkɑmpləˈmɛnʧi ˈdiˌɛˈneɪ/ ] | 互补DNA |
A DNA molecule synthesized from an RNA template using reverse transcriptase.
|
Unit 6 |
| antibiotics | [ /ˌæntibaɪˈɑtɪks/ ] | 抗生素 |
Substances that kill or inhibit the growth of bacteria.
|
Unit 6 |
| antibiotic resistance gene | [ /ˌæntibaɪˈɑtɪk rɪˈzɪstəns ʤin/ ] | 抗生素抗性基因 |
A gene (frequently carried on bacterial plasmids or transposons) that encodes proteins that neutralize, pump out, or destroy antibiotics, providing selective survival advantages.
|
Unit 6 |
| evolution | [ /ˌɛvəˈluʃən/ ] | 生物进化 |
The process by which populations of organisms change over generations through variations in their genetic composition.
|
Unit 7 |
| natural selection | [ /ˈnæʧərəl səˈlɛkʃən/ ] | 自然选择 |
The process where individuals with favorable traits are more likely to survive and reproduce, passing those traits to the next generation.
|
Unit 7 |
| overproduction | [ /ˈoʊvərprəˈdəkʃən/ ] | 过度繁殖 |
The evolutionary principle that organisms produce more offspring than the environment can support, creating intense competition for limited resources.
|
Unit 7 |
| fitness | [ /ˈfɪtnəs/ ] | 适应度 / 适应性 |
The ability of an organism to survive and reproduce in its environment.
|
Unit 7 |
| adaptation | [ /ˌædəpˈteɪʃən/ ] | 适应 / 适应特征 |
A heritable characteristic that improves an organism's ability to survive and reproduce in a specific environment.
|
Unit 7 |
| sexual selection | [ /ˈsɛkʃuəl səˈlɛkʃən/ ] | 性选择 |
A type of natural selection where individuals with certain traits are more likely to attract mates and reproduce.
|
Unit 7 |
| artificial selection | [ /ˌɑrtəˈfɪʃəl səˈlɛkʃən/ ] | 人工选择 |
The human-directed breeding of organisms to enhance desirable traits.
|
Unit 7 |
| selective breeding | [ /səˈlɛktɪv ˈbridɪŋ/ ] | 选择育种 |
The intentional, human-directed breeding of organisms with desirable phenotypic traits over generations to produce specialized varieties or breeds.
|
Unit 7 |
| directional selection | [ /dɪˈrɛkʃɪnəl səˈlɛkʃən/ ] | 定向选择 |
A form of selection that favors individuals at one extreme of a phenotypic range.
|
Unit 7 |
| disruptive selection | [ /dɪsˈrəptɪv səˈlɛkʃən/ ] | 分裂选择 / 歧化选择 |
A type of selection that favors individuals at both extremes of a trait, leading to a bimodal distribution.
|
Unit 7 |
| stabilizing selection | [ /ˈsteɪbəˌlaɪzɪŋ səˈlɛkʃən/ ] | 稳定选择 |
A mode of natural selection that favors intermediate phenotypic variants by acting against extreme phenotypes, reducing genetic and phenotypic variance within a population.
|
Unit 7 |
| fossil | [ /ˈfɑsəl/ ] | 化石 |
Preserved remains or traces of organisms that lived in the past.
|
Unit 7 |
| biogeography | [ /bˌaɪoʊɡˌɑːfiːˈɑːriːə/ ] | 生物地理学 |
The study of the distribution of species and ecosystems in geographic space and through geological time.
|
Unit 7 |
| homologous structure | [ /hɑˈmɑləgəs ˈstrəkʧər/ ] | 同源结构 |
Anatomical features that are similar in structure but may have different functions， indicating a common ancestry.
|
Unit 7 |
| common ancestor (common ancestry) | [ /ˈkɑmən ˈænˌsɛstər/ ] | 共同祖先 |
The shared ancestor of two or more species from which they evolved.
|
Unit 7 |
| species | [ /ˈspiʃiz/ ] | 物种 |
A group of organisms capable of interbreeding and producing viable, fertile offspring.
|
Unit 7 |
| viable | [ /ˈvaɪəbəl/ ] | 可存活的 |
Capable of surviving, developing normally, and maintaining metabolic independence in an environmental habitat.
|
Unit 7 |
| fertile | [ /ˈfərtəl/ ] | 具生殖能力的 / 可育的 |
Capable of producing viable, healthy gametes and successfully bearing offspring through sexual reproduction.
|
Unit 7 |
| sympatric speciation | [ /sɪmpˈɑːtrɪk spˌɛʃiːˈeɪʃən/ ] | 同域物种形成 |
The formation of new species within the same geographic area, often due to behavioral or ecological factors.
|
Unit 7 |
| speciation | [ /spˌɛʃiːˈeɪʃən/ ] | 物种形成 |
The evolutionary process by which new species arise.
|
Unit 7 |
| reproductive isolation | [ /ˌriprəˈdəktɪv ˌaɪsəˈleɪʃən/ ] | 生殖隔离 |
Barriers that prevent two populations from interbreeding and producing viable， fertile offspring.
|
Unit 7 |
| allopatric speciation | [ /ˌæləpˈætrɪk spˌɛʃiːˈeɪʃən/ ] | 异域物种形成 |
The formation of new species due to geographic isolation.
|
Unit 7 |
| prezygotic barrier | [ /prˌɛdʒəzˈɔːtɪk ˈbɛriər/ ] | 受精前隔离 / 合子前生殖隔离 |
A reproductive barrier that prevents fertilization from occurring between different species.
|
Unit 7 |
| postzygotic barrier | [ /pˌoʊstiːɡzˈɑːtɪk ˈbɛriər/ ] | 受精后隔离 / 合子后生殖隔离 |
A reproductive barrier that occurs after fertilization, often leading to inviable or sterile offspring.
|
Unit 7 |
| geographical isolation | [ /ˌʤiəˈgræfɪkəl ˌaɪsəˈleɪʃən/ ] | 地理隔离 |
A physical separation of populations by geographic barriers (mountains, rivers, canyons) that prevents gene flow and initiates allopatric speciation.
|
Unit 7 |
| habitat isolation | [ /ˈhæbəˌtæt ˌaɪsəˈleɪʃən/ ] | 栖息地隔离 / 生态隔离 |
A prezygotic reproductive barrier where two species inhabit different ecological niches within the same geographic area and rarely encounter each other to mate.
|
Unit 7 |
| temporal isolation | [ /ˈtɛmpərəl ˌaɪsəˈleɪʃən/ ] | 时间隔离 / 季节隔离 |
A prezygotic barrier in which related species breed at different times of the day, during different seasons, or in different years, preventing interbreeding.
|
Unit 7 |
| behavioral isolation | [ /bɪˈheɪvjərəl ˌaɪsəˈleɪʃən/ ] | 行为隔离 |
A prezygotic reproductive barrier characterized by differences in courtship rituals, vocalizations, or mating displays that prevent cross-mating between species.
|
Unit 7 |
| mechanical isolation | [ /məˈkænɪkəl ˌaɪsəˈleɪʃən/ ] | 机械隔离 / 形态隔离 |
A prezygotic barrier where anatomical and structural differences in reproductive organs physically prevent successful copulation or pollen transfer.
|
Unit 7 |
| gametic isolation | [ /ɡəmˈɛtɪk ˌaɪsəˈleɪʃən/ ] | 配子隔离 |
A prezygotic reproductive barrier where the sperm of one species is chemically incapable of fertilizing the egg of another species due to incompatible surface receptors.
|
Unit 7 |
| reduced hybrid viability | [ /rɪˈdust ˈhaɪbrɪd vaɪəˈbɪləti/ ] | 杂种存活率降低 |
A postzygotic barrier in which hybrid zygotes between two species fail to develop properly or survive to reproductive maturity due to genetic incompatibility.
|
Unit 7 |
| reduced hybrid fertility | [ /rɪˈdust ˈhaɪbrɪd fərˈtɪlɪti/ ] | 杂种不育 / 杂种育性降低 |
A postzygotic reproductive barrier where hybrid offspring develop into vigorous adults but are completely sterile due to failure in meiotic chromosome pairing (e.g., mules).
|
Unit 7 |
| hybrid breakdown | [ /ˈhaɪbrɪd ˈbreɪkˌdaʊn/ ] | 杂种衰败 / 杂种退化 |
A postzygotic barrier where first-generation (F1) interspecific hybrids are viable and fertile, but their offspring (F2) are feeble, malformed, or sterile.
|
Unit 7 |
| punctuated equilibrium | [ /ˈpəŋkʧuˌeɪtɪd ˌiːkwɪˈlɪbriəm/ ] | 间断平衡模式 |
The theory that evolutionary change occurs in rapid bursts followed by long periods ofstability.
|
Unit 7 |
| gradualism | [ /ˈgræʤəwəˌlɪzəm/ ] | 渐变模式 / 渐进式 |
The theory that evolution occurs through slow and steady changes over time.
|
Unit 7 |
| divergent evolution | [ /dɪˈvərʤənt ˌɛvəˈluʃən/ ] | 趋异进化 |
The process where related species evolve different traits, often due to different environments.
|
Unit 7 |
| adaptive radiation | [ /əˈdæptɪv ˌreɪdiˈeɪʃən/ ] | 适应辐射 |
The rapid evolution of diverse species from a common ancestor to exploit different ecological niches.
|
Unit 7 |
| convergent evolution | [ /kənˈvərʤənt ˌɛvəˈluʃən/ ] | 趋同进化 |
The process where unrelated species develop similar traits due to similar environmental pressures.
|
Unit 7 |
| analogous structure | [ /əˈnæləgəs ˈstrəkʧər/ ] | 同功结构 |
Structures with similar functions but different evolutionary origins.
|
Unit 7 |
| coevolution | [ /kˌoʊvəwˈɛlʃən/ ] | 协同进化 |
The reciprocal evolutionary influence between two or more species.
|
Unit 7 |
| phylogeny | [ /faɪˈlɑːdʒəni/ ] | 系统发生 / 种系发生 |
The evolutionary history and genealogical relationships of a species, higher taxon, or group of organisms over geological timescales.
|
Unit 7 |
| phylogenetic tree | [ /fˌaɪələdʒənˈɛtɪk tri/ ] | 系统发生树 |
A diagram that shows evolutionary relationships among species based on their common ancestry.
|
Unit 7 |
| cladogram | [ /ˈklædəɡræm/ ] | 进化分支图 |
A branching diagram that represents the evolutionary relationships among organisms based on shared characteristics.
|
Unit 7 |
| outgroup | [ /ˌaʊtɡrˈʌp/ ] | 外类群 / 外群 |
A species or group used for comparison that diverged before the species being studied.
|
Unit 7 |
| extinction | [ /ɪkˈstɪŋʃən/ ] | 生物灭绝 |
The permanent loss of all members of a species.
|
Unit 7 |
| Hardy-Weinberg equilibrium | [ /ˈhɑːrdi ˈwaɪnbɜːrɡ ˌiːkwɪˈlɪbriəm/ ] | 哈迪-温伯格平衡 |
A principle stating that allele frequencies in a population remain constant in the absence of evolutionary forces.
|
Unit 7 |
| allele frequency | [ /əˈliːl ˈfrikwənsi/ ] | 等位基因频率 |
The proportion of a specific allele in a population's gene pool.
|
Unit 7 |
| genotype frequency | [ /ˈdʒiːnətaɪp ˈfrikwənsi/ ] | 基因型频率 |
The proportion of individuals with a specific genotype in a population.
|
Unit 7 |
| genetic drift | [ /ʤəˈnɛtɪk drɪft/ ] | 遗传漂变 |
Random changes in allele frequencies in a population, especially in small populations.
|
Unit 7 |
| bottleneck effect | [ /ˈbɑtəlˌnɛk ˈifɛkt/ ] | 瓶颈效应 |
A severe reduction in genetic diversity occurring when a biological population undergoes an abrupt, drastic crash in size due to environmental catastrophes, overhunting, or habitat loss.
|
Unit 7 |
| founder effect | [ /ˈfaʊndər ˈifɛkt/ ] | 建立者效应 / 奠基者效应 |
Reduced genetic variation that occurs when a small group of individuals establishes a new population.
|
Unit 7 |
| RNA world hypothesis | [ /rˈeɪn wərld haɪˈpɑθəsəs/ ] | RNA世界假说 |
The hypothesis that early life forms relied on RNA for both genetic information and catalytic functions.
|
Unit 7 |
| gene flow | [ /ʤin floʊ/ ] | 基因流 / 基因漂流 |
The transfer of alleles from one population to another.
|
Unit 7 |
| Miller-Urey experiment | [ /ˈmɪlər ˈjʊəri ɪkˈspɛrɪmənt/ ] | 米勒-尤里实验 |
A landmark 1953 origin-of-life simulation demonstrating that organic compounds, including amino acids, could abioticly synthesize from an inorganic reducing atmosphere.
|
Unit 7 |
| ecology | [ /ɪˈkɑləʤi/ ] | 生态学 |
The study of how organisms interact with each other and their environment.
|
Unit 8 |
| organismal ecology | [ /ˈɔːrɡənzməsəl ɪˈkɑləʤi/ ] | 机体生态学 / 个体生态学 |
The branch of ecology that studies how an organism's structure, physiology, and behavior help it survive and reproduce in its environment.
|
Unit 8 |
| endotherm | [ /ˈɛndoʊθɜːrm/ ] | 恒温动物 / 内温动物 |
An organism that generates its own body heat through internal metabolic processes to maintain a relatively stable internal temperature independently of the ambient environment.
|
Unit 8 |
| ectotherm | [ /ˈɛktoʊθɜːrm/ ] | 变温动物 / 外温动物 |
An organism that relies predominantly on external environmental heat sources (such as solar radiation) to regulate its internal body temperature.
|
Unit 8 |
| altruism (altruistic behavior) | [ /ˈæltruˌɪzəm/ ] | 利他行为 |
Behavior that benefits another individual at a cost to oneself.
|
Unit 8 |
| kin selection | [ /kɪn səˈlɛkʃən/ ] | 亲缘选择 |
A type of natural selection where individuals increase their genetic fitness by helping relatives reproduce.
|
Unit 8 |
| population | [ /ˌpɑpjəˈleɪʃən/ ] | 种群 |
A group of individuals of the same species living in the same area at the same time.
|
Unit 8 |
| population growth | [ /ˌpɑpjəˈleɪʃən groʊθ/ ] | 种群增长 |
The change in the number of individuals of a biological species in a defined habitat over time, governed by birth rates, death rates, immigration, and emigration.
|
Unit 8 |
| exponential growth | [ /ˌɛkspoʊˈnɛnʃəl groʊθ/ ] | 指数增长 (J型增长) |
Rapid population increase in ideal conditions, represented by a J-shaped curve.
|
Unit 8 |
| logistic growth | [ /ləˈʤɪstɪk groʊθ/ ] | 逻辑斯谛增长 (S型增长) |
Population growth that slows as it approaches the carrying capacity, forming an S-shaped curve.
|
Unit 8 |
| density-dependent factor | [ /dˌɛnsɪtˈɪdpɪntɪd ˈfæktər/ ] | 密度制约因素 |
A factor whose effect on population size increases as population density rises, such as disease or competition.
|
Unit 8 |
| carrying capacity (K) | [ /ˈkæriɪŋ kəˈpæsɪti/ ] | 环境容纳量 (K值) |
The maximum number of individuals an environment can sustainably support.
|
Unit 8 |
| density-independent factor | [ /dˌɛnsɪtˈɪntɪdənt ˈfæktər/ ] | 非密度制约因素 |
A factor that affects population size regardless of density, such as weather or natural disasters.
|
Unit 8 |
| community | [ /kəmˈjunɪti/ ] | 生物群落 |
A group of interacting species living in the same area.
|
Unit 8 |
| species composition | [ /ˈspiʃiz ˌkɑmpəˈzɪʃən/ ] | 物种组成 |
The identity and relative abundance of all distinct biological species residing and interacting within a given ecological community.
|
Unit 8 |
| species diversity | [ /ˈspiʃiz dɪˈvərsɪti/ ] | 物种多样性 |
The variety of species in a community, including both richness and evenness.
|
Unit 8 |
| species richness | [ /ˈspiʃiz ˈrɪʧnəs/ ] | 物种丰富度 |
The total count of different biological species present in a defined ecological community or geographical area.
|
Unit 8 |
| species evenness | [ /ˈspiʃiz ˈivənnəs/ ] | 物种均匀度 |
A measure of the relative abundance and equitability of different biological species making up the total richness of an ecological community.
|
Unit 8 |
| Simpson's diversity index | [ /ˈsɪmpsənz daɪˈvɜːrsɪti ˈɪndɛks/ ] | 辛普森多样性指数 |
A mathematical quantitative metric (D = 1 - sum(n/N)^2) used to quantify biodiversity, taking into account both species richness and species evenness.
|
Unit 8 |
| ecological niche | [ /ɛkəˈlɑʤɪkəl nɪʧ/ ] | 生态位 |
The unique functional role, resource requirements, and environmental tolerance limits of a species within its ecosystem ('its ecological profession').
|
Unit 8 |
| competition | [ /ˌkɑmpəˈtɪʃən/ ] | 种间竞争 |
The struggle between organisms for the same limited resources in an ecosystem.
|
Unit 8 |
| niche partitioning | [ /nɪʧ pɑrˈtɪʃənɪŋ/ ] | 生态位分化 / 生态位隔离 |
The process by which competing species use resources in different ways to coexist.
|
Unit 8 |
| predation | [ /prəˈdeɪʃən/ ] | 捕食作用 |
A biological interaction in which one free-living organism (the predator) hunts, kills, and consumes another organism (the prey) for sustenance.
|
Unit 8 |
| predator | [ /ˈprɛdətər/ ] | 捕食者 |
An organism that naturally preys upon and consumes other organisms to obtain energy and nutrients.
|
Unit 8 |
| prey | [ /preɪ/ ] | 猎物 / 被捕食者 |
An animal hunted, caught, and consumed by a predator in a predator-prey relationship.
|
Unit 8 |
| herbivory | [ /hˈɜːrbɪvˌɔːriː/ ] | 植食作用 / 食草 |
A trophic interaction in which an herbivore consumes autotrophic plant tissues or algae without necessarily killing the whole plant organism.
|
Unit 8 |
| herbivore | [ /ˈərbɪˌvɔr/ ] | 植食性动物 |
A primary consumer adapted anatomically and physiologically to feed exclusively or primarily on autotrophic plants or algae.
|
Unit 8 |
| carnivore | [ /ˈkɑrnɪˌvɔr/ ] | 肉食性动物 |
A secondary or tertiary consumer that obtains nutritional energy primarily by eating animal tissue.
|
Unit 8 |
| food chain | [ /fud ʧeɪn/ ] | 食物链 |
A linear sequence showing how energy and nutrients flow from one organism to another.
|
Unit 8 |
| food web | [ /fud wɛb/ ] | 食物网 |
A complex network of interconnected food chains in an ecosystem.
|
Unit 8 |
| producer (primary producer) | [ /prəˈdusər/ ] | 生产者 |
An organism that creates its own food through photosynthesis or chemosynthesis.
|
Unit 8 |
| consumer | [ /kənˈsumər/ ] | 消费者 |
An organism that obtains energy by eating other organisms.
|
Unit 8 |
| trophic level | [ /trˈɑːfɪk ˈlɛvəl/ ] | 营养级 |
A step in the food chain or food web, representing an organism's position in the flow of energy.
|
Unit 8 |
| photoautotroph | [ /fˌoʊtoʊˈeɪtərhəp/ ] | 光能自养生物 |
An autotroph that uses sunlight to produce energy through photosynthesis.
|
Unit 8 |
| chemoautotroph | [ /kˈɛməθˌɔːrəθ/ ] | 化能自养生物 |
An autotroph that uses chemical energy to produce food through chemosynthesis.
|
Unit 8 |
| autotroph | [ /ˈɔːtətrɑːf/ ] | 自养生物 |
An organism that produces its own food from inorganic sources.
|
Unit 8 |
| chemosynthesis | [ /kˌɛmoʊsˈɛnətsnəs/ ] | 化能合成作用 |
The process by which certain organisms produce energy-rich compounds using chemical energy instead of light.
|
Unit 8 |
| heterotroph | [ /ˈhɛtərətrɑːf/ ] | 异养生物 |
An organism that obtains energy by consuming other organisms.
|
Unit 8 |
| 10% rule (ten percent law) | [ /rul/ ] | 10%能量传递原则 |
The principle that only about 10% of the energy at one trophic level is transferred to the next.
|
Unit 8 |
| bottom-up model | [ /ˈbɑtəˌməp ˈmɑdəl/ ] | 自下而上调控模型 |
A model that suggests the availability of resources at the lowest trophic level determines the structure of the ecosystem.
|
Unit 8 |
| top-down model | [ /ˈtɔpˌdaʊn ˈmɑdəl/ ] | 自上而下调控模型 |
An ecological trophic control model postulating that predation by apex predators predominantly regulates the abundance, biomass, and diversity of lower trophic levels.
|
Unit 8 |
| trophic pyramid | [ /trˈɑːfɪk ˈpɪrəmɪd/ ] | 生态金字塔 / 营养级金字塔 |
A graphical representation of energy or biomass distribution among trophic levels.
|
Unit 8 |
| trophic cascade | [ /trˈɑːfɪk kæˈskeɪd/ ] | 营养级联效应 |
An ecological phenomenon triggered by the addition or removal of top predators, cascading reciprocal changes in predator-prey dynamics across two or more lower trophic levels.
|
Unit 8 |
| symbiosis | [ /ˌsɪmbaɪˈoʊsɪs/ ] | 共生关系 |
A close, long-term interaction between two different species.
|
Unit 8 |
| mutualism | [ /ˈmjuːtʃuəlɪzəm/ ] | 互利共生 |
A type of symbiosis where both species benefit from the interaction.
|
Unit 8 |
| parasitism | [ /ˈpærəsɪtɪzəm/ ] | 寄生 |
A type of symbiosis where one organism benefits while the other is harmed
|
Unit 8 |
| parasite | [ /ˈpɛrəˌsaɪt/ ] | 寄生生物 / 寄生虫 |
An organism that lives on or inside a host organism and benefits by deriving nutrients at the host organism's expense, often causing physiological harm.
|
Unit 8 |
| host | [ /hoʊst/ ] | 宿主 / 寄主 |
An organism that harbors and provides nutritional sustenance or shelter to a symbiotic parasite or mutualistic organism.
|
Unit 8 |
| commensalism | [ /kəˈmɛnsəlɪzəm/ ] | 偏利共生 (共栖) |
A type of symbiosis where one organism benefits and the other is neither helped nor harmed.
|
Unit 8 |
| decomposer | [ /dˌiːkəmpˈoʊzər/ ] | 分解者 |
An organism (such as fungi and bacteria) that digests and breaks down dead organic matter and metabolic wastes into essential inorganic nutrients, recycling them through the ecosystem.
|
Unit 8 |
| decomposition | [ /ˌdikəmpəˈzɪʃən/ ] | 分解作用 |
The process by which decomposers break down dead organisms and recycle nutrients back into the ecosystem.
|
Unit 8 |
| keystone species | [ /ˈkiˌstoʊn ˈspiʃiz/ ] | 关键物种 |
A species that has a disproportionately large effect on its ecosystem relative to its abundance.
|
Unit 8 |
| ecosystem | [ /ˈikoʊˌsɪstəm/ ] | 生态系统 |
A biological community and its physical environment interacting as a system.
|
Unit 8 |
| biotic factor | [ /bˌaɪətˈɛk ˈfæktər/ ] | 生物因素 |
A living component of an ecosystem, such as plants or animals.
|
Unit 8 |
| ecosystem diversity | [ /ˈikoʊˌsɪstəm dɪˈvərsɪti/ ] | 生态系统多样性 |
The variety of biological communities, habitats, and ecological processes operating within a given geographical region or biome.
|
Unit 8 |
| abiotic factor | [ /ˌæbiːˈɑːtɪk ˈfæktər/ ] | 非生物因素 |
A non-living component of an ecosystem, such as sunlight, water, or temperature.
|
Unit 8 |
| biodiversity | [ /ˌbaɪoʊdaɪˈvərsəti/ ] | 生物多样性 |
The variety of life in all its forms, levels, and combinations within an ecosystem.
|
Unit 8 |
| invasive species | [ /ˌɪnˈveɪsɪv ˈspiʃiz/ ] | 入侵物种 |
A non-native species that spreads rapidly and causes harm to ecosystems.
|
Unit 8 |