生物专业英语第三版蒋悟生编--课文翻译及课后单词.doc
《生物专业英语第三版蒋悟生编--课文翻译及课后单词.doc》由会员分享,可在线阅读,更多相关《生物专业英语第三版蒋悟生编--课文翻译及课后单词.doc(32页珍藏版)》请在咨信网上搜索。
1、生物专业英语(第三版)Inside 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
2、 by 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
3、丝状的细胞骨架支撑。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
4、 organelles-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
5、pores.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)All eukaryotic cells contain most of the various kinds of organelles, and each organelle performs a specialized function in the cell. O
6、rganelles 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 few hund
7、red 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 move along a
8、 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 proteins and
9、 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, and vesicles,
10、 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.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。粗糙内质网上分布许多核糖体,也可能提供细胞分裂后所需
11、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 particular areas in or outs
12、ide 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 export out of the cell or
13、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 reservoirs and storage sites f
14、or 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 lysosomes, which contain diges
15、tive enzymes (packaged in lysosomes in the Golgi complex) that can break down most biological macromolecules. 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 chemical reactions in all cells.
16、 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 self-replicating, and probably t
17、hey 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 storage sites for starch, proteins, and o
18、ils; 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 matrix called the stroma.质体有两种类型:白
19、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 cell and provides support for vari
20、ous other organelles. A large portion of the cytoskeleton consists of threadlike 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, is involve in the contraction of muscle ce
21、lls. 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 tensile strength to the cell cytoplasm. Mech
22、anoenzymes 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
23、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 by creeping 爬行 or gliding 滑动. Such movements
24、 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 chemical.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
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 生物 专业 英语 第三 版蒋悟生编 课文 翻译 课后 单词
1、咨信平台为文档C2C交易模式,即用户上传的文档直接被用户下载,收益归上传人(含作者)所有;本站仅是提供信息存储空间和展示预览,仅对用户上传内容的表现方式做保护处理,对上载内容不做任何修改或编辑。所展示的作品文档包括内容和图片全部来源于网络用户和作者上传投稿,我们不确定上传用户享有完全著作权,根据《信息网络传播权保护条例》,如果侵犯了您的版权、权益或隐私,请联系我们,核实后会尽快下架及时删除,并可随时和客服了解处理情况,尊重保护知识产权我们共同努力。
2、文档的总页数、文档格式和文档大小以系统显示为准(内容中显示的页数不一定正确),网站客服只以系统显示的页数、文件格式、文档大小作为仲裁依据,平台无法对文档的真实性、完整性、权威性、准确性、专业性及其观点立场做任何保证或承诺,下载前须认真查看,确认无误后再购买,务必慎重购买;若有违法违纪将进行移交司法处理,若涉侵权平台将进行基本处罚并下架。
3、本站所有内容均由用户上传,付费前请自行鉴别,如您付费,意味着您已接受本站规则且自行承担风险,本站不进行额外附加服务,虚拟产品一经售出概不退款(未进行购买下载可退充值款),文档一经付费(服务费)、不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
4、如你看到网页展示的文档有www.zixin.com.cn水印,是因预览和防盗链等技术需要对页面进行转换压缩成图而已,我们并不对上传的文档进行任何编辑或修改,文档下载后都不会有水印标识(原文档上传前个别存留的除外),下载后原文更清晰;试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓;PPT和DOC文档可被视为“模板”,允许上传人保留章节、目录结构的情况下删减部份的内容;PDF文档不管是原文档转换或图片扫描而得,本站不作要求视为允许,下载前自行私信或留言给上传者【天****】。
5、本文档所展示的图片、画像、字体、音乐的版权可能需版权方额外授权,请谨慎使用;网站提供的党政主题相关内容(国旗、国徽、党徽--等)目的在于配合国家政策宣传,仅限个人学习分享使用,禁止用于任何广告和商用目的。
6、文档遇到问题,请及时私信或留言给本站上传会员【天****】,需本站解决可联系【 微信客服】、【 QQ客服】,若有其他问题请点击或扫码反馈【 服务填表】;文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“【 版权申诉】”(推荐),意见反馈和侵权处理邮箱:1219186828@qq.com;也可以拔打客服电话:4008-655-100;投诉/维权电话:4009-655-100。