1、生物工程专业英语1Inside the Living Cell: Structure andFunction of Internal Cell PartsCytoplasm: The Dynamic, Mobile Factory细胞质：动力工厂Most of the properties we associate with life are properties of the cytoplasm. Much of the mass of a cell consists of this semifluid substance, which is bounded on the outside b
2、y the plasma membrane. Organelles are suspended within it, supported by the filamentous network of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins, and other materials needed for cell functioning.生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状
3、的细胞骨架支撑。细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。The Nucleus: Information Central（细胞核：信息中心）The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus also contains one or two o
4、rganelles-the nucleoli-that play a role in cell division. A pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such as mRNA and ribosomes must enter and exit via the po
5、res.真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小分子可以自由通过核膜，而象 mRNA 和核糖体等大分子必须通过核孔运输。Organelles: Specialized Work Units（细胞器：特殊的功能单位）生物工程专业英语2All eukaryotic cells contain most of the various kinds of organelles, and each organelle performs a specialized function in th
6、e cell. Organelles described in this section include ribosomes, the endoplasmic reticulum, the Golgi complex, vacuoles, lysosomes, mitochondria, and the plastids of plant cells.所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。The number of ribosomes within a cell may range from a
7、 few hundred to many thousands. This quantity reflects the fact that, ribosomes are the sites at which amino acids are assembled into proteins for export or for use in cell processes. A complete ribosome is composed of one larger and one smaller subunit. During protein synthesis the two subunits mov
8、e along a strand of mRNA, “reading“ the genetic sequence coded in it and translating that sequence into protein. Several ribosomes may become attached to a single mRNA strand; such a combination is called a polysome. Most cellular proteins are manufactured on ribosomes in the cytoplasm. Exportable p
9、roteins and membrane proteins are usually made in association with the endoplasmic reticulum.核糖体的数量变化从几百到几千，核糖体是氨基酸组装成蛋白质的重要场所。完整的核糖体由大亚基和小亚基组成。核糖体沿着 mRNA 移动并阅读遗传密码，翻译成蛋白质。一条 mRNA 上可能有多个核糖体，称多聚核糖体。大多数细胞蛋白是由细胞质中核糖体生产。输出蛋白和膜蛋白通常与内质网有关。The endoplasmic reticulum, a lacy array of membranous sacs, tubules
10、, and vesicles, may be either rough (RER) or smooth (SER). Both types play roles in the synthesis and transport of proteins. The RER, which is studded with polysomes, also seems to be the source of the nuclear envelope after a cell divides.生物工程专业英语3内质网，带有花边的生物囊，有管状，泡状之分，以及光滑和粗糙面区别。两种都与蛋白质的合成和运输有关。粗糙
11、内质网上分布许多核糖体，也可能提供细胞分裂后所需的细胞膜。SER lacks polysomes; it is active in the synthesis of fats and steroids and in the oxidation of toxic substances in the cell. Both types of endoplasmic reticulum serve as compartments within the cell where specific products can be isolated and subsequently shunted to par
12、ticular areas in or outside the cell.光滑内质网上无核糖体，主要作用是脂肪和类固醇的合成以及细胞内有毒物质的氧化。两种内质网合成的产物在其中进行分流或运输到细胞外。Transport vesicles may carry exportable molecules from the endoplasmic reticulum to another membranous organelle, the Golgi complex. Within the Golgi complex molecules are modified and packaged for ex
13、port out of the cell or for delivery else where in the cytoplasm.运输小泡能够将可运输分子从内质网运输到高尔基复合体上。在高尔基复合体中修饰，包装后输出细胞或传递到细胞质中的其他场所。Vacuoles in cells appear to be hollow sacs but are actually filled with fluid and soluble molecules. The most prominent vacuoles appear in plant cells and serve as water reserv
14、oirs and storage sites for sugars and other molecules. Vacuoles in animal cells carry out phagocytosis (the intake of particulate matter) and pinocytosis (vacuolar drinking).细胞中的液泡好象是中空的，但实际上充满了液体和可溶分子。最典型的液泡存在于植物细胞中，储备水，糖以及其它分子。动物中的液泡起吞噬和胞饮作用。 A subset of vacuoles are the organelles known as lysoso
15、mes, which contain digestive enzymes (packaged in lysosomes in the Golgi complex) that can break down most biological 生物工程专业英语4macromolecules. They act to digest food particles and to degrade damaged cell parts.溶酶体是液泡亚单位，含有消化酶，降解大部分生物大分子。消化食物微粒和降解损伤的细胞残片。Mitochondria are the sites of energy-yielding
16、 chemical reactions in all cells. In addition, plant cells contain plastids that utilize light energy to manufacture carbohydrates in the process of photosynthesis. It is on the large surface area provided by the inner cristae of mitochondria that ATP-generating enzymes are located. Mitochondria are
17、 self-replicating, and probably they are the evolutionary descendants of what were once free-living prokaryotes.线粒体是细胞中化学产能的场所。另外，植物细胞中的质体在光合作用中利用光能产生碳水化合物，线粒体内嵴上提供了很大的表面积并分布着产 ATP 酶。线粒体自我复制，并且可能是自由生活的原核生物在进化中形成的后代。There are two types of plastids: leucoplasts, which lack pigments and serve as storag
18、e sites for starch, proteins, and oils; and chromoplasts, which contain pigments. The most important chromoplasts are chloroplasts-organelles that contain the chlorophyll used in photosynthesis. The internal structure of chloroplasts includes stacks of membranes called grana, which are embedded in a
19、 matrix called the stroma.质体有两种类型：白色体，缺乏色素，是淀粉，蛋白质和油的储备场所；色质体，含有色素。叶绿体是最重要的色质体，含有与光合作用有关的叶绿素。叶绿体的内部结构是由多层膜形成的叶绿体基粒，其中包埋在基质中的基粒称子座。The Cytoskeleton（细胞骨架）All eukaryotic cells have a cytoskeleton, which is a convoluted latticework of filaments and tubules that appears to fill all available space in the
20、 cell and provides support for various other organelles. A large portion of the cytoskeleton consists of 生物工程专业英语5threadlike microfilaments composed mainly of the contractile protein actin. They are involved in many types of intracellular movements in plant and animal cells. A second protein, myosin
21、, is involve in the contraction of muscle cells. Another main structural component of the cytoskeleton consists of microtubules, which are composed of the globular protein tubulin and together act as scaffolding that provides a stable cell shape. Cytoskeletal intermediate filaments appear to impart
22、tensile strength to the cell cytoplasm. Mechanoenzymes such as myosin, dynein, and kinesin interact with the cytoskeletal filaments and tubules to generate forces that cause movements.所有的细胞都有细胞骨架，网络结构的纤丝充满了它所能触及的全部空间并且对细胞器提供支持作用。细胞骨架大部分由微丝组成，微丝主要由可收缩的肌动蛋白组成。动植物细胞的许多种类型细胞内运动与肌动蛋白有关。第二类蛋白是肌球蛋白，它与肌肉细胞的
23、收缩有关。细胞骨架的另一个主要结构成分是微管，由球状的微管蛋白组成，象脚手架一般维持细胞的稳定形态。细胞骨架的中间丝提供了细胞质伸缩动力。机械酶，例如，肌球蛋白，动力蛋白，驱动蛋白与微丝，微管相互作用产生动力而引起细胞运动。Cellular Movements（细胞运动 Although the cytoskeleton provides some stability 稳固 to cells, its microtubules英maikrutju:bju:l and filaments 丝状物 and their associated proteins enable cells to move
24、 by creeping 爬行 or gliding 滑动. Such movements require a solid 固体的 substrate to which the cell can adhere 附着 and can be guided by the geometry dimitri 几何形状 of the surface. Some cells also exhibit izibit 展览 chemotaxis, kemtksis 趋药性 the ability to move toward or away from the source of a diffusing 扩散 c
25、hemical.生物工程专业英语6尽管细胞骨架提供了细胞的某些稳定性，微丝，微管及相关蛋白能使细胞爬行或滑动。这种运动需要固体基质依托并通过表面几何形状的改变而运动。某些细胞具备趋药性，即趋向或逃离扩散开的化学源。Certain eukaryotic cells can swim freely in liquid environments, propelled by whiplike cilia sili纤毛 or flagella 英fldel鞭毛. Both cilia and flagella have the same internal structure: nine doublets
26、 (pairs of microtubules) are arranged in a ring and extend the length of the cilium or flagellum, and two more microtubules run down the center of the ring. Every cilium or flagellum grows only from the cell surface where a basal body 基体 is located. Movement is based on the activities of tiny dynein
27、 动力蛋白 side arms that extend from one of the microtubules of each doublet 成对的东西.某些真核细胞能在液体液体中自由运动，由纤毛或鞭毛推动。纤毛和鞭毛具有同样的内部结构：九个双微管环形排列，纵向延伸，环中心是两个或以上微管组成。纤毛或鞭毛从细胞表面的基体出生长，双微管的动力蛋白臂从一侧延伸到另一侧而引起运动。Nutrients, proteins, and other materials within most plant cells are moved about via cytoplasmic streaming. T
28、he process occurs as myosin maiusin 肌凝蛋白 proteins attached to organelles 细胞器,小器官 push against microfilaments arrayed rei 展示throughout the cell. Microfilaments and microtubules are responsible for almost all major cytoplasmic movements. During cell division, microtubules of the spindle assembled 集合,
29、收集 from tubutin subunits near organelles called centrioles move the chromosomes.大部分植物细胞的营养，蛋白质和其它物质由细胞质流运输。这个过程是由于依附在细胞器上的肌球蛋白反推排列在细胞周围的微丝形成的。绝大部分细胞质运动由微丝和微管生物工程专业英语7完成。在细胞分裂期间，中心粒周围的由微管蛋白亚基装配形成的纺锤体微管移向染色体。Glossarycytoplasm （细）胞质The living contents of a cell bounded externally by the plasmalemma, in
30、cluding an aqueous ground substance (hyaloplasm, cell sap, or cell matrix) containing organelles and various inclusions but excluding the nucleus and visible vacuoles.cytoskeleton 细胞骨架Of eukaryotic cells, an internal “skeleton“. Its microtubules and other components structurally support the cell, or
31、ganize and move its inteftial components. The cytoskeleton also helps free-living cells move through their environment. nucleus 细胞核，核(复数 nuclei)The organelle of the eukaryote cell that contains the chromosomes and hence ultimately controls cellular activity and inheritance through the activity of th
32、e genetic material, DNAchromosome 染色体A DNA-histone thread residing in the nucleus of a cell. Each chromosome possesses two telomeres and a centromere, and some contain a nucleolus organizer. RNA proteins are invariably associated with the chromosome. nucleoid 拟核，类核，核质体The DNA-containing area of a pr
33、okaryote cell, analogous to the eukaryote nucleus but not membrane bounded.nucleoli 核仁( 单数 nucleolus) Nuclear structures composed of completed or partially completed ribosomes and the specific parts of chromosomes that contain the infon-nation for their construction. nuclear envelope 核膜，核被膜生物工程专业英语8
34、A double membrane (two lipid bilayers and associated proteins) that is the outermost portion of a cell nucleus. ribosome 核糖体Small structures composed of two protein and ribonucleic acid subunits involved in the assembly of proteins from amino acids.polysome 多核糖体Of protein synthesis, several ribosome
35、s all translating the same messenger RNA molecule,one after the other.endoplasmic reticulum 内质网Folded membranes and tubes throughout the eukaryotic cell that provide a large surface upon which chemical activities take place.Golgi complex 高尔基复合体A stack of flattened, smooth, membranous sacs; the site
36、of synthesis and packaging of certain molecules in eukaryotic cells.vacuole 液泡Storage container within the cytoplasm of a cell having a surrounding membrane.phagocytosis 吞噬作用The process by which the cell wraps around a particle and engulfs it.pinocytosis 胞饮作用The process by which a cell engulfs some
37、molecules dissolved in waterlysosome 溶酶体A specialized organelle that holds a mixture of hydrolytic enzymes.mitochondrion 线粒体(复数 mitochondria )A membranous organelle resembling a small bag with a larger bag resembling a small bag with a larger bag inside that is folded back on itself; serves as the s
38、ite of aerobic cellular respiration.plastid 质体生物工程专业英语9An organelle present in all plants except bacteria, blue-green algae, and fungi; it is enclosed by two membranes (the envelope) and has various functionschloroplast 叶绿体A plastid in which photosynthesis is carried out. Chloroplasts occur in all p
39、hotosynthetic organisms except photosynthetic bacteria blue-green algae.stroma 基质，子座（复数 stromata）Region within a chloroplast that has no chlorophyll.microfilament 微丝，纤丝Long, fiberlike structures made of protein and found in cells, often in close association with the microtubules; provide structural
40、support and enable movement.actin 肌动蛋白 A globular contractile protein. In muscle cells, actin interacts with another protein, myosin, to bring about contraction. myosin maiesin 肌球蛋白A protein that, with actin, constitutes the principal element of the contractile apparatus of muscle.microtubute 微管Smal
41、l, hollow tubes of protein that function throughout the cytoplasm to provide structural support and enable movement.tubulin 微管蛋白A protein that is the major constituent of microtubules.dynein 动力蛋白，动素A group of at least four distinct proteins found in the flagella and microtubules of eukaryotic cells
42、and possessing ATPase activity. chemotaxis 趋化性A locomotory movement of an organism or cell in response to, and directed by, an directional stimulus.cilia 纤毛Numerous short, hairlike structures projecting from the cell surface that enable locomotion. 生物工程专业英语10flagella 鞭毛 (单数 flagellum) Long, hairlike
43、 structures projecting from the cell surface that enable locomotion.basal body 基体A body identical in structure to a centriole, found always at the base of a cilium or eukaryote flagellum.centriole 中心粒 An organelle located close to the nucleus in most animal and lower plant cells but absent from prokaryotes and higher plants.
