《生物科学专业英语》PPT课件.ppt

生物专业英语,InsidetheLivingCell,StructureandFunctionofInternalCellparts,Glossary,Cytoplasm细胞质Thelivingcontentsofacellboundedexternallybytheplasmalemma,includinganaqueousgroundsubstance(hyaloplasm,透明质，cellsap,orcellmatrix)containingorganellesandvariousinclusionsbutexcludingthenucleusandvisiblevacuoles.,细胞中的亚器官,Chloroplast叶绿体Aplastidinwhichphotosynthesisiscarriedout.Chloroplastsoccurinallphotosyntheticorganismsexceptphotosyntheticbacteriaandblue-greenalgae.,Stroma子座，基质Regionwithinachloroplastthathasnochlorophyll.Plastid质体Anorganellepresentinallplantsexceptbacteria,blue-greenalgae,andfungi;itisenclosedbytwomembranes(theenvelope)andhasvariousfunctions,Endoplasmicreticulum内质网Foldedmembranesandtubesthroughouttheeukaryoticcellthatprovidealargesurfaceuponwhichchemicalactivitiestakeplace.,Golgicomplex高尔基复合体Astackofflattened,smooth,memebranoussacs;thesiteofsynthesisandpackagingofcertainmoleculesineukaryoticcells.,Mitochondrion线粒体Amembranousorganelleresemblingasmallbagwithalargerbaginsidethatisfoldedbackonitself;serveasthesiteofaerobiccellularrespiration.,Ribosome核糖体Smallstructurescomposedoftwoproteinandribonucleicacidsubunitsinvolvedintheassemblyofproteinsfromaminoacids,Polysome多核糖体Ofproteinsynthesis,severalribosomesalltranslatingthesamemessengerRNAmolecule,oneaftertheother.,Vacuole液泡Storagecontainerwithinthecytoplasmofacellhavingasurroundingmembrane.,Lysosome溶酶体AspecializedorganellethatholdsamixtureofhydrolyticenzymesCentriole中心粒Anorganellelocatedclosetothenucleusinmostanimalandlowerplantcellsbutabsentfromprokaryotesandhigherplants,细胞的遗传亚结构,细胞核和染色体,Chromosome染色体ADNA-histonethreadresidinginthenucleusofacell.Eachchromosomepossessestwotelomeresandacentromere,andsomecontainanucleousorganizer.RNAproteinsareinvariablyassociatedwiththechromosome.,Nuclearenvelope核膜，核被膜Adoublemembrane(twolipidbilayersandassociatedproteins)thatistheoutermostportionofacellnucleous.Nucleoid核质体TheDNA-containingareaofaprokaryotecell,analogoustoeukaryotenucleusbutnotmembranebounded.Nucleoli核仁Nuclearstructurescomposedofcompletedorpartiallycompletedribosomesandthespecificpartsofchromosomesthatcontaintheinformationfortheirconstruction.,Nucleus细胞核，神经核Theorganelleoftheeukaryotecellthatcontainsthechromosomesandhenceultimatelycontrolscellularactivityandinheritancethroughtheactivityofthegeneticmaterial,DNA.,细胞运动结构和骨架,Cytoskeleton细胞骨架Ofeukaryoticcells,aninternal“skeleton”.Itsmicrotubulesandothercomponentsstructurallysupportthecell,organizeandmoveitsinternalcomponents.Thecytoskeletonalsohelpsfree-livingcellsmovethroughtheirenvironment.,Microtubule微管Small,hollowtubesofproteinthatfunctionthroughoutthecytoplasmtoprovidestrucuturalsupportandenablemovement.Microfilament微丝，纤丝Long,fiberlikestructuresmadeofproteinandfoundincells,oftenincloseassociationwiththemicrotubule;providestructuralsupportandenablemovement.,Cilia纤毛Numerousshort,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion.Flagella鞭毛Long,hairlikestructuresprojectingfromthecellsurfacethatenablelocomotion.,Actin肌动蛋白Aglobularcontractileprotein.Inmusclecells,actininteractswithanotherprotein,myosein,tobringaboutcontraction.Dynein动力蛋白AgroupofatleastfourdistinctproteinsfoundintheflagellaandmicrotubulesofeukaryoticcellsandpossessingATPaseactivity.Myosin肌球蛋白Aproteinthat,withactin,constitutestheprincipalelementofthecontractileapparatusofmuscle.,Tubulin微管蛋白Aproteinthatisthemajorconstituentofmicrotubules.,Basalbody基体Abodyidenticalinstructuretoacentriole,foundalwaysatthebaseofaciliumoreukaryoteflagellum.Chemotaxis趋化性Alocomotorymovementofanorganismorcellinresponseto,anddirectedby,anexternaldirectionalstimulus.,Phagocytosis吞噬作用Theprocessbywhichthecellwrapsaroundaparticleandengulfsit.Pinocytosis胞饮作用Theprocessbywhichacellengulfssomemoleculesdissolvedinwater.,胞饮作用,Cytoplasm细胞质Thedynamic,MobileFactory,Semifluid半流体Plasmamembrane质膜Organelle细胞器官Cytoskeleton细胞骨架,Mostofthepropertiesweassociatedwithlifearepropertiesofthecytoplasm.Muchofthemassofacellconsistsofthissemifluidsubstance,whichisboundedontheoutsidebytheplasmamembrane.,Organellesaresuspendedwithinit,supportedbythefilamentousnetworkofthecytoskeleton.Dissolvedinthecytoplasmicfluidarenutrients,ions,solubleproteins,andothermaterialsneededforcellfunctioning.,Nucleus细胞核,Eukaryotic真核细胞的Prokaryote原核细胞Hereditary遗传的Sac液囊,细胞核和染色体,Theeukaryoticcellnucleusisthelargestorganelleandhousesthegeneticmaterial(DNA)onchromosomes.Inprokaryotesthehereditarymaterialisfoundinthenucleoid.Thenucleusalsocontainsoneortwoorgenelles-thenucleoli-thatplayaroleincelldivision.,Apore-perforatedsaccalledthenuclearenvelopeseparatesthenucleusanditscontentsfromthecytoplasm.Smallmoleculescanpassthroughthenuclearenvelope,butlargermoleculessuchasMRNAandribosomesmustenterandexitviathepores,Organelle细胞器官,Aminoacid氨基酸Lacy花边Vesicle小泡Stud布满Fat脂肪Steroid胆固醇Oxidation氧化Sugar糖,digestive消化的carbohydrate碳水化合物Leucoplast白色体Pigment色素Starch淀粉Chromoplast色素细胞Grana叶绿素基粒,细胞结构,Alleukaryoticcellscontainmostofthevariouskindsoforganelles,andeachorganelleperformsaspecializedfunctioninthecell.Organellesdescribedinthissectionincluderibosomes,theendoplasmicreticulum,theGolgicomplex,vacuoles,mitochondria,andtheplastidsofplantcells.,Thenumberofribosomeswithinacellmayrangefromafewhundredtomanythousands.Thisquantityreflectsthefactthatribosomesarethesitesatwhichaminoacidsareassembledintoproteinsforexportorforuseincellprocesses.Acompleteribosomeiscomposedofonelargerandonesmallersubunit.,DuringproteinsynthesisthetwosubunitsmovealongastrandofMRNA,“reading”thegeneticsequencecodedinitandtranslatingthatsequenceintoprotein.SeveralribosomesmaybecomeattachedtoasingleMRNAstrand;suchacombinationiscalledapolysome.,Mostcellularproteinsaremanufacturedonribosomesinthecytoplasm.Exportableproteinsandmembraneproteinsareusuallymadeinassociationwiththeendoplasmicreticulum.,Theendoplasmicreticulum,alacyarrayofmembranoussacs,tubules,andvesicles,maybeeitherrough(RER)andsmooth(SER).Bothtypesplayrolesinthesynthesisandtransportofproteins.TheRER,whichisstuddedwithpolysomes,alsoseemstobethesourceofthenuclearenvelopeafteracelldivides.,SERlackspolysomes;itisactiveinthesynthesisoffatsandsteroidsandintheoxidationoftoxicsubstanceinthecell.Bothtypesofendoplasmicreticulumserveascompartmentswithinthecellwherespecificproductscanbeisolatedandsubsequentlyshuntedtoparticularareasinoroutsidethecell.,内质网,Transportvesiclesmaycarryexportablemoleculesfromtheendoplasmicreticulumtoanothermembranousorganelle,theGolgicomplex.WithintheGolgicomplexmoleculesaremodifiedandpackagedforexportoutofthecellorfordeliveryelsewhereinthecytoplasm.,高尔基体,液泡,Vacuolesincellsappeartobehollowsacsbutareactuallyfilledwithfluidandsolublemolecules.Themostprominentvaculoesappearinplantcellsandserveaswaterreservoirsandstoragesitesforsurgarsandothermolecules.,Vacuolesinanimalcellscarryoutphagocytosis(吞噬作用)(theintakeofparticulatematter)andpinocytosis(胞饮作用)(vacuolardrinking).,胞饮作用,Asubsetofvacuolesistheorganellesknownaslysosomeswhichcontaindigestiveenzymes(packagedinlysosomesintheGolgicomplex)thatcanbreakdownmostbiologicalmacromolecules.Theyacttodigestfoodparticlesandtodegradedamagedcellparts.,线粒体,Mitochondriaarethesitesofenergy-yieldingchemicalreactionsinallcells.inaddition,plantcellscontainplastidsthatutilizelightenergytomanufacturecarbohydratesintheprocessofphotosynthesis.,ItisonthelargesurfaceareaprovidedbytheinnercristaeofmitochondriathatATP-generatingenzymesarelocated.Mitochondriaareself-replicating,andprobablytheyaretheevolutionarydescendantsofwhatwereoncefree-livingprokaryotes.,叶绿体立体结构,Therearetwotypesofplastids,leucoplasts(白色体),whichlackpigmentsandserveasstoragesitesforstarch,proteins,andoils;andchromoplasts(色素母细胞),whichcontainpigments.Themostimportantchromoplastsarechloroplasts-organellesthatcontainthechlorophyllusedinphotosynthesis.,Theinternalstructureofchloroplastsincludesstacksofmembranescalledgrana(叶绿体基粒),whichareembedded,inamatrixcalledthestroma(基质).,Cytoskeleton细胞骨架,Convoluted回旋Latticework格子状Mechanoenzyme功能酶Kinesin运动蛋白,Alleukryotescellshaveacytoskeleton,whichisaconvolutedlatticeworkoffilamentsandtubulesthatappearstoavailablespaceinthecellandprovidessupportforvariousotherorganelles.,Alargeportionofthecytoskeletonconsistsofthreadlikemicrofilamentscomposedmainllyofthecontractileproteinactin.Theyareinvolvedinmanytypesofintracellularmovementsinplantandanimalcells.,Asecondprotein,myosinisinvolveinthecontractionofmusclecells.Anothermainstructuralcomponentofthecytoskeletonconsistsofmicrotubules,whicharecomposedoftheglobularproteintubulinandtogetheractasscaffoldingthatprovidesastablecellshape.,Cytoskeletalintermediatefilamentsappeartoimparttensilestrengthtothecellcytoplasm.Mechanoenzymessuchasmyosin,dyneinandkinesininteractwiththecytoskeletalfilamentsandtubulinstogenerateforcesthatcausemovements.,Cellularmovements细胞运动,Creep爬行Glide滑动Geometry几何Propel推动Spindle纺锤体,Althoughthecytosketetonprovidessomestabilitytocells,itsmicrotubulesandfilamentsandtheirassociatedproteinsenablecellstomovebycreepingorgliding.,Suchmovementsrequireasubstratetowhichthecellcanadhereandcanbeguidedbythegeometryofthesurface.Somecellsalsoexhibitchemotaxis,theabilitytomovetowardorawayfromthesourceofadiffusingchemical.,Certaineukaryoticcellscanswimfreelyinliquidenvironments,propelledbywhiplikecilia(纤毛)andflagella（鞭毛）.Bothciliaandflagellahavethesameinternalstructure:ninedoublets(pairsormicrotubules)arearragedinaringandextendthelengthoftheciliumorflagellum,andtwomoremicrotubulesrundowntheenterofthering.,Everyciliumorflagellumgrowsonlyfromthecellsurfacewhereabasalbodyislocated.Movementisbasedontheactivitiesoftinydyneinsi