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LessonOneInsidetheLivingCell:StructureandFunctionofInternalCellParts1.Knowing the Component of the cell.2.Describe the relationship between cell shape and cell function.3.Distinguish between prokaryotes and eukaryotes structure.4.Introduce the structures and functions of different types of cell organelles.Glossary:Cyto-细胞Cytology：细胞学Cytoplasm：细胞质Cytokinesis：胞质分裂Cytoskeleton：细胞骨架Cytobiology：细胞生物学Cytocentrum：中心体chloroplast:叶绿体chlorophyll:叶绿素carotenoid:类胡萝卜素:carotene:胡萝卜素lutein:叶黄素Accessorypigment:辅助色素nucleus:细胞核（pl:nuclei）nucleoli:核仁nucleoid:拟核，类核nuclearenvelope:核膜nuclearpore:核孔Pinocytosis:胞饮作用Phagocytosis:吞噬作用ribosome 核糖体polysome 多核糖体 endoplasmic reticulum 内质网Golgi complex 高尔基复合体lysosome 溶酶体mitochondrion 线粒体 plastid 质体basalbody:基体cilia:纤毛flagella:鞭毛stroma 基质，子座 microfilament 微丝，纤丝actin 肌动蛋白 myosin 肌球蛋白microtubule 微管tubulin 微管蛋白dynein 动力蛋白 chemotaxis 趋化性cilia 纤毛flagella 鞭毛(单数flagellum)basal body基体centriole 中心粒 Cytoplasm 细胞质细胞质The living contents of a cell bounded externally by the plasmalemma,including an aqueous ground substance(hyaloplasm,透明透明质，质，cell sap,or cell matrix)containing organelles and various inclusions but excluding the nucleus and visible vacuoles.1.Cytoplasm:TheDynamic,MobileFactoryMostofthepropertiesweassociatewithlifearepropertiesofthecytoplasm.Muchofthemassofacellconsistsofthissemifluidsubstance,whichisboundedontheoutsidebytheplasmamembrane.细胞质：动力工厂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，并由原生质膜包被。Organellesaresuspendedwithinit,supportedbythefilamentousnetworkofthecytoskeleton.Dissolvedinthecytoplasmicfluidarenutrients,irons,solubleproteins,andothermaterialsneededforcellfunctioning.细胞器悬浮在其中，并由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。nucleus 细胞核，核(复数 nuclei)Theorganelleoftheeukaryotecellthatcontainsthechromosomesandhenceultimatelycontrolscellularactivityandinheritancethroughtheactivityofthegeneticmaterial,DNA2.TheNucleus:InformationCentral（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 organelles-the nucleoli-that play a role in cell division.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。Apore-performatedsaccalledthenuclearenvelopesepatatesthenucleusanditscontentsfromthecytoplasm.Smallmoleculescanpassthroughthenuclearenvelope,butlargemoleculessuchasmRNAandribosomesmustenterandexitviathepores.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。3.Organelles:Specialized Work Units（细胞器：特殊的功能单位）Alleukaryoticcellscontainmostofthevariouskindsoforganelles,andeachorganelleperformsaspecializedfunctioninthecell.Organellesdescribedinthissectioninclude ribosomes,theendoplasmic reticulum,theGolgicomplex,vacuoles,lysosomes,mitochondria,andtheplastidsofplantcells.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。Ribosome核糖体 Small structures composed of two protein and ribonucleic acid subunits involved in the assembly of proteins from amino acidsThenumberofribosomes withinacellmayrangefromafewhundredtomanythousands.Thisquantityreflectsthefactthat,ribosomesarethesitesatwhichaminoacidsareassembledintoproteinsforexportorforuseincellprocesses.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。Acompleteribosomeiscomposedofonelargerandonesmallersubunit.DuringproteinsynthesisthetwosubunitsmovealongastrandofmRNA,“reading”thegeneticsequencecodedinitandtranslatingthatsequenceintoprotein.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。SeveralribosomesmaybecomeattachedtoasinglemRNAstrand;suchacombinationiscalledapolysome.一条一条mRNA上可能有多个核糖体，称多聚核糖体。上可能有多个核糖体，称多聚核糖体。Polysome 多核糖体 Of protein synthesis,several ribosomes all translating the same messenger RNA molecule,one after the other.Most cellular proteins are manufactured on ribosomes in the cytoplasm.Exportable proteins and membrane proteins are usually made in association with the endoplasmic reticulum.大多数细胞蛋白是由细胞质中核糖体生产。输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。出蛋白和膜蛋白通常与内质网有关。Theendoplasmic reticulum,alacyarrayofmembranoussacs,tubules,andvesicles,maybeeitherrough(RER)orsmooth(SER).Bothtypesplayrolesinthesynthesisandtransportofproteins.TheRER,whichisstudded withpolysomes,alsoseemstobethesourceofthenuclearenvelopeafteracelldivides.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的细胞膜。Endoplasmic reticulum 内质网内质网 Folded membranes and tubes throughout the eukaryotic cell that provide a large surface upon which chemical activities take place.SERlackspolysomes;itisactiveinthesynthesisoffatsandsteroidsandintheoxidationoftoxicsubstancesinthecell.Bothtypesofendoplasmicreticulumserveascompartmentswithinthecellwherespecificproductscanbeisolatedandsubsequentlyshuntedtoparticularareasinoroutsidethecell.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。Golgi complex 高尔基复合体高尔基复合体 A stack of flattened,smooth,memebranous sacs;the site of synthesis and packaging of certain molecules in eukaryotic cells.Transportvesiclesmaycarryexportablemoleculesfromtheendoplasmicreticulumtoanothermembranousorganelle,thegolgicomplex,withintheGoligcomplexmoleculesaremodifiedandpackagedforexportoutofthecellorfordeliveryelsewhereinthecytoplasm.运输小泡能够将可运输的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 incellsappeartobehollowsacsbutareactuallyfilledwithfluidandsolublemolecules.Themostprominentvacuolesappearinplantcellsandserveaswaterreservoirsandstoragesitesforsugarsandothermolecules.Vacuolesinanimalcellscarryoutphagocytosis(theintakeofparticulatematter)andpinocytosis(vacuolardrinking).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。Vacuole 液泡 Storage container within the cytoplasm of a cell having a surrounding membrane.Phagocytosis吞噬作用Theprocessbywhichthecellwrapsaroundaparticleandengulfsit.Pinocytosis胞饮作用Theprocessbywhichacellengulfssomemoleculesdissolvedinwater.Asubsetofvacuolesaretheorganellesknownaslysosomes,whichcontaindigestiveenzymes(packagedinlysosomesintheGolgicomplex)thatcanbreakdownmostbiologicalmacromolecules.Theyacttodigestfoodparticlesandtodegradedamagedcellparts.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。Mitochondrion 线粒体线粒体 A membranous organelle resembling a small bag with a larger bag inside that is folded back on itself;serve as the site of aerobic cellular respiration.Mitochondriaarethesitesofenergy-yieldingchemicalreactionsinallcells.Inaddition,plantcellscontainplastidsthatutilizelightenergytomanufacturecarbohydratesintheprocessofphotosynthesis.Itisonthelargesurfaceareaprovidedbytheinnercristae（嵴）ofmitochondriathatATP-generatingenzymesarelocated.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。Mitochondriaareself-replicating,andprobablytheyaretheevolutionarydescendantsofwhatwereoncefree-livingprokaryotes.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 oils;and chromoplasts,which contain pigments.质体有两种类型：白色体，缺乏色素，是淀质体有两种类型：白色体，缺乏色素，是淀粉，蛋白质和油的储备场所；色质体，含有色粉，蛋白质和油的储备场所；色质体，含有色素。素。Themostimportantchromoplastsarechloroplasts-organelles thatcontainthechlorophyllusedinphotosynthesis.Theinternalstructureofchloroplastsincludesstacksofmembranescalledgrana,whichareembeddedinamatrixcalledthestroma.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。Chloroplast 叶绿体叶绿体 A plastid in which photosynthesis is carried out.Chloroplasts occur in all photosynthetic organisms except photosynthetic bacteria and blue-green algae.Stroma子座，基质 Regionwithinachloroplastthathasnochlorophyll.Plastid质体 Anorganellepresentinallplantsexceptbacteria,blue-greenalgae,andfungi;itisenclosedbytwomembranes(theenvelope)andhasvariousfunctions.The Cytoskeleton（细胞骨架）Alleukaryoticcellshaveacytoskeleton,whichisaconvoluted（回旋）latticework(格子状)offilamentsandtubulesthatappearstofillallavailablespaceinthecellandprovidessupportforvariousotherorganelles.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。Cytoskeleton细胞骨架 Of eukaryotic cells,an internal“skeleton”.Its microtubules and other components structurally support the cell,organize and move its internal components.The cytoskeleton also helps free-living cells move through their environment.Alargeportionofthecytoskeletonconsistsofthreadlikemicrofilaments composedmainlyofthecontractileproteinactin.Theyareinvolvedinmanytypesofintracellularmovementsinplantandanimalcells.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。Microtubule 微管微管 Small,hollowtubesofproteinthatfunctionthroughoutthecytoplasmtoprovidestrucutualsupportandenablemovement.Microfilament 微丝，纤丝微丝，纤丝 Long,fiberlikestructuresmadeofproteinandfoundincells,oftenincloseassociationwiththemicrotubule;providestructuralsupportandenablemovement.Asecondprotein,myosin,isinvolveinthecontractionofmusclecells.Anothermainstructuralcomponentofthecytoskeletonconsistsofmicrotubules,whicharecomposedoftheglobularproteintubulin andtogetheractasscaffoldingthatprovidesastablecellshape.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的稳定形态。ACytoskeletalintermediatefilamentsappeartoimparttensilestrengthtothecellcytoplasm.Mechanoenzymessuchasmyosin,dynein,andkinesininteractwiththecytoskeletalfilamentsandtubulestogenerateforcesthatcausemovements.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 to cells,its microtubules and filaments and their associated proteins enable cells to move by creeping or gliding.尽管细胞骨架提供了细胞的某些稳定性，微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。丝，微管及相关蛋白能使细胞爬行或滑动。Such movements require a solid substrate to which the cell can adhere and can be guided by the geometry of the surface.Some cells also exhibit chemotaxis,the ability to move toward or away from the source of a diffusing chemical.这种运动需要固体基质依托并通过表面几何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。某些细胞具备趋化性，形状的改变而运动。某些细胞具备趋化性，即趋向或逃离扩散开的化学源。即趋向或逃离扩散开的化学源。Chemotaxis 趋化性趋化性 Alocomotorymovementofanorganismorcellinresponseto,anddirectedby,anexternaldirectionalstimulus.Certain eukaryotic cells can swim freely in liquid environments,propelled by whiplike cilia or flagella.Both cilia and flagella have the same internal structure:某些真核细胞能在液体中自由运动，由纤毛某些真核细胞能在液体中自由运动，由纤毛或鞭毛推动。纤毛和鞭毛具有同样的内部结构或鞭毛推动。纤毛和鞭毛具有同样的内部结构：Cilia 纤毛纤毛 Numerousshort,hairlikestructuresprojecting（突出）fromthecellsurfacethatenablelocomotion.Flagella 鞭毛鞭毛 Long,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion.nine doublets(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.九个双微管环形排列，纵向延伸，环中心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。是两个或以上微管组成。Every cilium or flagellum grows only from the cell surface where a basal body is located.Movement is based on the activities of tiny dynein side arms that extend from one of the microtubules of each doublet.纤毛或鞭毛从细胞表面的基体出生长，双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微管的动力蛋白臂从一侧延伸到另一侧而引起运动。起运动。Basalbody基体 Abodyidenticalinstructuretoacentriole,foundalwaysatthebaseofaciliumoreukaryoteflagellum.Nutrients,proteins,and other materials within most plant cells are moved about via cytoplasmic streaming.The process occurs as myosin proteins attached to organelles push against microfilaments arrayed throughout the cell.大部分植物细胞的营养，蛋白质和其它物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细胞器上的肌球蛋白反推排列在细胞周围的微丝形成的。微丝形成的。Microfilaments and microtubules are responsible for almost all major cytoplasmic movements.During cell division,microtubules of the spindle assembled from tubulin subunits near organelles called centrioles move the chromosomes.绝大部分细胞质运动由微丝和微管完成。绝大部分细胞质运动由微丝和微管完成。在细胞分裂期间，中心粒周围的由微管蛋白亚在细胞分裂期间，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。基装配形成的纺锤体微管移向染色体。
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