CellStructureandFunction細(xì)胞結(jié)構(gòu)和功能(84)課件

1CellStructureandFunctionLecture11CellStructureandFunctionL2OutlineCellularLevelofOrganizationCelltheoryCellsizeProkaryoticCellsEukaryoticCellsOrganellesNucleusandRibosomeEndomembraneSystemOtherVesiclesandVacuolesEnergyrelatedorganellesCytoskeletonCentrioles,Cilia,andFlagella2OutlineCellularLevelofOrga3CellTheoryCellwasnotdiscovereduntillthedevelopmentofMicroscopeDetailedstudyofthecellbeganinthe1830sAunifyingconceptinbiologyStatesthat:AllorganismsarecomposedofcellsAllcellscomeonlyfrompreexistingcellsCellsarethesmalleststructuralandfunctionalunitoforganismsCellscarrygeneticinformationintheformofDNA3CellTheoryCellwasnotdisco4SizesofLivingThings4SizesofLivingThings5CellSizeCellsrangeinsizefromonemillimeterdowntoonemicrometerCellsneedalargesurfaceareaofplasmamembranetoadequatelyexchangematerials.Thesurface?area?to?volumeratiorequiresthatcellsbesmall5CellSizeCellsrangeinsize6SurfacetoVolumeRatio6SurfacetoVolumeRatio7MicroscopyToday:CompoundLightMicroscopeLightpassedthroughspecimenFocusedbyglasslensesMaxmagnificationabout1000XResolvesobjectsseparatedby0.2mm,500XbetterthanhumaneyeResolutionislimitedbythewavelengthoflight(nanometer)7MicroscopyToday:CompoundLi8CompoundLightMicroscopeDiaphragm–controlsamountoflight–importantforimagecontrastCoarseAdjustmentKnob–focusestheimageFineAdjustmentKnob–finelyfocusestheimage8CompoundLightMicroscopeDiap9MicroscopyToday:Transmission

ElectronMicroscopeAbbreviatedT.E.M.Usesabeamofelectronstoallow100foldhighermagnificationBecauseitusesbeamofelectrons,itsresolutionisattheatomiclevel(picometer)TissuemustbefixedandsectionedCanlivingspecimenbeexaminedbyT.E.M?9MicroscopyToday:Transmissio10TransmissionElectronMicroscope10TransmissionElectronMicros11MicroscopyToday:ImmunofluorescenceLightMicroscopeAntibodiesdevelopedagainstaspecificproteinFluorescentdyemoleculeattachedtoantibodymoleculesSpecimenexposedtofluorescentantibodiesUltra-violetlight(blacklight)passedthroughspecimenFluorescentdyeglowsincolorwhereantigenislocatedEmittedlightisfocusedbyglasslensesontohumanretinaAllowsmappingdistributionofaspecificproteinincell11MicroscopyToday:Immunofluo12MicroscopyandAmoebaproteus12MicroscopyandAmoebaproteuCellsUndertheMicroscopephase-contrastlightmicroscope-lookatunstainedlivinganimalcells.electronmicroscope-lookatorganellese.g.ribosomes.fluorescencemicroscope-lookatalivingcellexpressinggreenfluorescentproteinortodoconfocalmicroscopy.CellsUndertheMicroscopephasAutoradiographyRadioactivecompoundsdecayortransformintoothercompoundsorelements.Anautoradiographisanimageonanx-rayfilmornuclearemulsionproducedbythepatternofdecayemissions(e.g.,betaparticlesorgammarays)fromadistributionofaradioactivesubstanceAutoradiographycanalsousesradioactivemoleculetostudybiochemicalactivity,Proteinsynthesis14AutoradiographyRadioactivecom15CellFractionationandDifferentialCentrifugationCellfractionationisthebreakingapartofcellularcomponentsDifferentialcentrifugation:AllowsseparationofcellpartsSeparatedoutbysize&densityWorkslikespincycleofwasherThefasterthemachinespins,thesmallerthepartsthataresettledout15CellFractionationandDiffe16CellFractionationandDifferentialCentrifugation16CellFractionationandDiffeEukaryotesVsProkaryotesEukaryoticCellsProkaryoticCellsThecellsof“complex”organisms,includingallplants,Protists,fungiandanimals“Simple”organisms,includingbacteriaandcyanobacteria(blue-greenalgae)ContainanucleusandmembraneboundorganellesLackanucleusandothermembrane-encasedorganelles.Canspecializeforcertainfunctions,suchasabsorbingnutrientsfromfoodortransmittingnerveimpulses;multicellularorgansandorganismsUsuallyexistassingle,virtuallyidenticalcellsCellWallpresentinPlantsandFungionlyRibosome:40s,60SCellWallRibosome:30S,50S17EukaryotesVsProkaryotesEukar18TheStructureofBacteriaOccurinthreebasicshapes:Sphericalcoccus,Rod-shapedbacillus,Spiralspirillum(ifrigid)orspirochete(ifflexible).CellEnvelopeincludes:Plasmamembrane-lipidbilayerwithimbeddedandperipheralproteinCellwall-maintainstheshapeofthecell18TheStructureofBacteriaOc19TheStructureofBacteria19TheStructureofBacteria20TheStructureofBacteria20TheStructureofBacteria21TheStructureofBacteriaCytoplasm&AppendagesCytoplasmSemifluidsolutionBoundedbyplasmamembraneContainswater,inorganicandorganicmolecules,andenzymes.Nucleoidisaregionthatcontainsthesingle,circularDNAmolecule.Plasmidsaresmallaccessory(extrachromosomal)ringsofDNAAppendagesFlagella–ProvidemotilityFimbriae–small,bristle-likefibersthatsproutfromthecellsurfaceSexpili–rigidtubularstructuresusedtopassDNAfromcelltocell21TheStructureofBacteriaCy22EukaryoticCellsDomainEukaryaincludes:ProtistsFungiPlantsAnimalsCellscontain:Membrane-boundnucleusthathousesDNASpecializedorganellesPlasmamembraneMuchlargerthanprokaryoticcellsSomecells(e.g.,plantcells)haveacellwall

22EukaryoticCellsDomainEukar23HypothesizedOriginofEukaryoticCells23HypothesizedOriginofEukar24EukaryoticCells:OrganellesEukaryoticcellsarecompartmentalizedTheycontainsmallstructurescalledorganellesPerformspecificfunctionsIsolatesreactionsfromothersTwoclassesoforganelles:Endomembranesystem:OrganellesthatcommunicatewithoneanotherViamembranechannelsViasmallvesiclesEnergyrelatedorganellesMitochondria&chloroplastsBasicallyindependent&self-sufficient24EukaryoticCells:Organelles25PlasmaMembrane25PlasmaMembrane26AnimalCellAnatomy26AnimalCellAnatomy27PlantCellAnatomy27PlantCellAnatomyCytosoleCytosol,containsmanylong,finefilamentsofproteinthatareresponsibleforcellshapeandstructureandtherebyformthecell’scytoskeleton28CytosoleCytosol,containsmany29NucleusCommandcenterofcell,usuallynearcenterSeparatedfromcytoplasmbynuclearenvelopeConsistsofdoublelayerofmembraneNuclearporespermitexchangebetweennucleoplasm&cytoplasmContainschromatininsemifluidnucleoplasmChromatincontainsDNAofgenes,andproteins(Histones)CondensestoformchromosomesChromosomesareformedduringcelldivisionNucleolusisadensestructureinthenucleusSynthesizeribosomeRNA(rRNA)29NucleusCommandcenterofcel30AnatomyoftheNucleus30AnatomyoftheNucleus31RibosomesArethesiteofproteinsynthesisinthecellComposedofrRNAandproteinConsistsofalargesubunitandasmallsubunitSubunitsmadeinnucleolusMaybelocated:Ontheendoplasmicreticulum(therebymakingit“rough”),orFreeinthecytoplasm31RibosomesArethesiteofpro32Nucleus,Ribosomes,&ER32Nucleus,Ribosomes,&ER33EndomembraneSystemSeriesofintracellularmembranesthatcompartmentalizethecellRestrictenzymaticreactionstospecificcompartmentswithincellConsistsof:NuclearenvelopeMembranesofendoplasmicreticulumGolgiapparatusVesiclesSeveraltypesTransportmaterialsbetweenorganellesofsystem33EndomembraneSystemSeriesof34EndomembraneSystem:

TheEndoplasmicReticulumAsystemofmembranechannelsandsaccules(flattenedvesicles)continuouswiththeoutermembraneofthenuclearenvelopeRoughERStuddedwithribosomesoncytoplasmicsideProteinanabolismSynthesizesproteinsModifiesandprocessesproteinsAddssugartoproteinResultsinglycoproteinsSmoothERNoribosomesSynthesisoflipidsSiteofvarioussyntheticprocesses,detoxification,andstorageFormstransportvesicles

34EndomembraneSystem:

TheEnd35EndoplasmicReticulum35EndoplasmicReticulum36EndomembraneSystem:

TheGolgiApparatusGolgiApparatusConsistsofflattened,curvedsacculesResemblesstackofhollowpancakesModifiesproteinsandlipidsReceivesvesiclesfromERoncis(orinnerface)ModifiesthemandrepackagestheminvesiclesReleasethevesiclesfromtrans(orouterface)WithincellExportfromcell(secretion,exocytosis)36EndomembraneSystem:

TheGol37GolgiApparatus37GolgiApparatus38EndomembraneSystem:LysosomesMembrane-boundvesicles(notinplants)ProducedbytheGolgiapparatusContainpowerfuldigestiveenzymesandarehighlyacidicDigestionoflargemoleculesRecyclingofcellulardebrisandresourcesAutolysismayoccurininjuredordyingcelltocauseapoptosis(programmedcelldeath,liketadpolelosingtail)38EndomembraneSystem:Lysosom39Lysosomes39Lysosomes40EndomembraneSystem:SummaryProteinsproducedinroughERandlipidsfromsmoothERarecarriedinvesiclestotheGolgiapparatus.TheGolgiapparatusmodifiestheseproductsandthensortsandpackagesthemintovesiclesthatgotovariouscelldestinations.Secretoryvesiclescarryproductstothemembranewhereexocytosisproducessecretions.Lysosomesfusewithincomingvesiclesanddigestmacromolecules.40EndomembraneSystem:Summary41EndomembraneSystem:AVisualSummary41EndomembraneSystem:AVisua42PeroxisomesSimilartolysosomesMembrane-boundedvesiclesEncloseenzymesthatridthecelloftoxicperoxidesParticipateinthemetabolismoffattyacidsandmanyothermetabolites42PeroxisomesSimilartolysoso43Peroxisomes43Peroxisomes44VacuolesMembranoussacsthatarelargerthanvesiclesStorematerialsthatoccurinexcessOthersveryspecialized(contractilevacuole)PlantscellstypicallyhaveacentralvacuoleUpto90%volumeofsomecellsFunctionsin:Storageofwater,nutrients,pigments,andwasteproductsDevelopmentofturgorpressureSomefunctionsperformedbylysosomesinothereukaryotes44VacuolesMembranoussacsthat45Vacuoles45Vacuoles46Energy-RelatedOrganelles:

ChloroplastStructureBoundedbydoublemembraneInnermembraneinfoldedFormsdisc-likethylakoids,whicharestackedtoformgranaSuspendedinsemi-fluidstromaChlorophyllGreenphotosyntheticpigmentChlorophyllcapturesolarenergy46Energy-RelatedOrganelles:

C47Energy-RelatedOrganelles:ChloroplastsServeasthesiteofphotosynthesisCaptureslightenergytodrivecellularmachineryPhotosynthesisSynthesizescarbohydratesfromCO2&H2OMakesownfoodusingCO2asonlycarbonsourceInorganicmolecules(Energy-poorcompounds)areconvertedtoorganicmolecules(energy-richcompounds)Onlyplants,algae,andcertainbacteriaarecapableofconductingphotosynthesis47Energy-RelatedOrganelles:C48ChloroplastStructure48ChloroplastStructure49Energy-RelatedOrganelles:MitochondriaSmallerthanchloroplastContainribosomesandtheirownDNASurroundedbyadoublemembraneInnermembranesurroundsthematrixandisconvoluted(folds)toformcristae.Matrix–InnersemifluidcontainingrespiratoryenzymesBreakdowncarbohydratesInvolvedincellularrespirationProducemostofATPutilizedbythecellContaintheirownDNAandribosomei.e.theyaresemiautonomousInheritedfromOocyte49Energy-RelatedOrganelles:M50MitochondrialStructure50MitochondrialStructureMitochondrialOriginHypothesis51MitochondrialOriginHypothesi52TheCytoskeletonMaintainscellshapeAssistsinmovementofcellandorganellesAidsmovementofmaterialsinandoutofcellsThreetypesofmacromolecularfibersMicrofilamentIntermediateFilamentsMicrotubulesAssembleanddisassembleasneeded52TheCytoskeletonMaintainsce53TheCytoskeleton:ActinFilamentsMicrofilamentarerodsofactinExtremelythinfilamentsliketwistedpearlnecklaceSupportformicrovilliinintestinalcellsIntracellulartrafficcontrolFormovingstuffaroundwithincellCytoplasmicstreamingFunctioninpseudopodsofamoeboidcellsImportantcomponentinmusclecontraction53TheCytoskeleton:ActinFila54TheCytoskeleton:ActinFilamentOperation54TheCytoskeleton:ActinFila55TheCytoskeleton:IntermediateFilamentsIntermediateinsizebetweenactinfilamentsandmicrotubulesRope-likeassemblyoffibrouspolypeptidesFunctions:SupportnuclearenvelopeCell-celljunctions,likethoseholdingskincellstightlytogether55TheCytoskeleton:Intermedia56TheCytoskeleton:MicrotubulesHollowcylindersmadeoftwoglobularproteinscalledaandbtubulinSpontaneouspairingofaandbtubulinmoleculesformstructurescalleddimersDimersthenarrangethemselvesintotubularspiralsof13dimersaroundAssembly:UndercontrolofMicrotubuleOrganizingCenter(MTOC)MostimportantMTOCiscentrosomeFunction:ProvideframeworkformovementoforganellewithincellDirectseparationofchromosomesduringcelldivision(e.g.Centriolesarecomposedofmicrotubules)Providelocomotionandmovement(e.g.flagellaandcilia)56TheCytoskeleton:Microtubul57TheCytoskeleton:MicrotubuleOperation57TheCytoskeleton:Microtubul58TheCytoskeleton58TheCytoskeleton59MicrotubularArrays:CentriolesShort,hollowcylindersOnepairperanimalcellLocatedincentrosomeofanimalcellsOrientedatrightanglestoeachotherSeparateduringmitosistodetermineplaneofdivision59MicrotubularArrays:Centrio60Cytoskeleton:Centrioles60Cytoskeleton:Centrioles61MicrotubularArrays:CiliaandFlagellaHair-likeprojectionsfromcellsurfacethataidincellmovementIneukaryotes,ciliaaremuchshorterthanflagellaCiliamoveincoordinatedwaveslikeoarsFlagellamovelikeapropellerorcorkscrew61MicrotubularArrays:Ciliaa62StructureofaFlagellum62StructureofaFlagellum63ComparisonofProkaryoticandEukaryoticCells63ComparisonofProkaryotican64MembraneStructureandFunctionLecture164MembraneStructureandFunct65OutlineMembraneModelsFluid-MosaicPlasmaMembraneStructureandFunctionPhospholipidsProteinsPlasmaMembranePermeabilityDiffusionOsmosisTransportViaCarrierProteinsCellSurfaceModifications65OutlineMembraneModels66StructureandFunction:

ThePhospholipidBilayerTheplasmamembraneiscommontoallcellsSeparates:InternallivingcytoplasmicfromExternalenvironmentofcellPhospholipidbilayer:ExternalsurfacelinedwithhydrophilicpolarheadsCytoplasmicsurfacelinedwithhydrophilicpolarheadsNonpolar,hydrophobic,fatty-acidtailssandwichedinbetween66StructureandFunction:

The67UnitMembrane67UnitMembrane68MembraneModelsFluid-MosaicModelThreecomponents:BasicmembranereferredtoasphospholipidbilayerProteinmoleculesFloataroundlikeicebergsonaseaMembraneproteinsmaybeperipheralorintegralPeripheralproteinsarefoundontheinnermembranesurfaceIntegralproteinsarepartiallyorwhollyembedded(transmembrane)inthemembraneSomehavecarbohydratechainsattachedCholesterol68MembraneModelsFluid-Mosaic69TheFluidMosaicModel69TheFluidMosaicModel70TransmembraneProteins70TransmembraneProteins71FunctionsofMembraneProteinsChannelProteins:TubularAllowpassageofmoleculesthroughmembraneCarrierProteins:CombinewithsubstancetobetransportedAssistpassageofmoleculesthroughmembraneCellRecognitionProteins:ProvidesuniquechemicalIDforcellsHelpbodyrecognizeforeignsubstancesReceptorProteins:BindswithmessengermoleculeCausescelltorespondtomessageEnzymaticProteins:Carryoutmetabolicreactionsdirectly71FunctionsofMembraneProtei72MembraneProteinDiversity72MembraneProteinDiversity73ScienceFocus:CellSignaling73ScienceFocus:CellSignalin74TypesofTransport:Activevs.PassivePlasmamembraneisdifferentially(selectively)permeableAllowssomematerialtopassInhibitspassageofothermaterialsPassiveTransport:NoATPrequirementMoleculesfollowconcentrationgradientActiveTransportRequirescarrierproteinRequiresenergyinformofATP74TypesofTransport:Activev75PassageofMoleculesAcrosstheMembrane75PassageofMoleculesAcross76TypesofMembraneTransport:Overview76TypesofMembraneTransport:77TypesofTransport:DiffusionAsolutionconsistsof:Asolvent(liquid),andAsolute(dissolvedsolid)DiffusionNetmovementofsolutemoleculesdownaconcentrationgradientMoleculesmovebothwaysalonggradientMoleculesmovefromhightolowEquilibrium:WhenNETchangestopsSoluteconcentrationuniform–nogradient77TypesofTransport:Diffusio78GasExchangeinLungs:DiffusionAcrossLung78GasExchangeinLungs:Diffu79TypesofTransport:OsmosisOsmosis:SpecialcaseofdiffusionFocusesonsolvent(water)movementratherthansoluteDiffusionofwateracrossadifferentially(selectively)permeablemembraneSoluteconcentrationononesidehigh,butwaterconcentrationlowSoluteconcentrationonothersidelow,butwaterconcentrationhighWaterdiffusesbothwaysacrossmembranebutsolutecan’tNetmovementofwateristowardlowwater(highsolute)concentrationOsmoticpressureisthepressurethatdevelopsduetoosmosis79TypesofTransport:OsmosisO80TypesofTransport:CarrierProteinsFacilitatedTransportSmallmoleculesCan’tgetthroughmembranelipidsCombinewithcarrierproteinsFollowconcentrationgradientActiveTransportSmallmoleculesMoveagainstconcentrationgradientCombiningwithcarrierproteinsRequiresenergy80TypesofTransport:Carrier81TypesofTransport:CarrierProteinsFacilitatedTransportSmallmoleculesCan’tgetthroughmembranelipidsCombinewithcarrierproteinsFollowconcentrationgradientActiveTransportSmallmoleculesMoveagainstconcentrationgradientCombiningwithcarrierproteinsRequiresenergy81TypesofTransport:Carrier82TypesofTransport:

Membrane-AssistedTransportMacromoleculestransportedintooroutofthecellinsidevesiclesExocytosis–VesiclesfusewithplasmamembraneandsecretecontentsEndocytosis–CellsengulfsubstancesintopouchwhichbecomesavesiclePhagocytosis–Large,solidmaterialintovesiclePinocytosis–Liquidorsmall,solidparticlesgointovesicleReceptor-Mediated–Specificformofpinocytosisusingacoatedpit82TypesofTransport:

Membrane83CellSurfaceModifications:JunctionsCellSurfacesinAnimalsJunctionsBetweenCellsAdhesionJunctionsIntercellularfilamentsbetweencellsTightJunctionsFormimpermeablebarriersGapJunctionsPlasmamembranechannelsarejoined(allowscommunication)83CellSurfaceModifications:84CellSurfaceModificationsExtracellularMatrixExternalmeshworkofpolysaccharidesandproteinsFoundincloseassociationwiththecellthatproducedthemPlantCellWallsPlantshavefreelypermeablecellwall,withcelluloseasthemaincomponentPlasmodesmatapenetratecellwallEachcontainsastrandofcytoplasmAllowpassageofmaterialbetweencells84CellSurfaceModificationsEx85CellStructureandFunctionLecture11CellStructureandFunctionL86OutlineCellularLevelofOrganizationCelltheoryCellsizeProkaryoticCellsEukaryoticCellsOrganellesNucleusandRibosomeEndomembraneSystemOtherVesiclesandVacuolesEnergyrelatedorganellesCytoskeletonCentrioles,Cilia,andFlagella2OutlineCellularLevelofOrga87CellTheoryCellwasnotdiscovereduntillthedevelopmentofMicroscopeDetailedstudyofthecellbeganinthe1830sAunifyingconceptinbiologyStatesthat:AllorganismsarecomposedofcellsAllcellscomeonlyfrompreexistingcellsCellsarethesmalleststructuralandfunctionalunitoforganismsCellscarrygeneticinformationintheformofDNA3CellTheoryCellwasnotdisco88SizesofLivingThings4SizesofLivingThings89CellSizeCellsrangeinsizefromonemillimeterdowntoonemicrometerCellsneedalargesurfaceareaofplasmamembranetoadequatelyexchangematerials.Thesurface?area?to?volumeratiorequiresthatcellsbesmall5CellSizeCellsrangeinsize90SurfacetoVolumeRatio6SurfacetoVolumeRatio91MicroscopyToday:CompoundLightMicroscopeLightpassedthroughspecimenFocusedbyglasslensesMaxmagnificationabout1000XResolvesobjectsseparatedby0.2mm,500XbetterthanhumaneyeResolutionislimitedbythewavelengthoflight(nanometer)7MicroscopyToday:CompoundLi92CompoundLightMicroscopeDiaphragm–controlsamountoflight–importantforimagecontrastCoarseAdjustmentKnob–focusestheimageFineAdjustmentKnob–finelyfocusestheimage8CompoundLightMicroscopeDiap93MicroscopyToday:Transmission

ElectronMicroscopeAbbreviatedT.E.M.Usesabeamofelectronstoallow100foldhighermagnificationBecauseitusesbeamofelectrons,itsresolutionisattheatomiclevel(picometer)TissuemustbefixedandsectionedCanlivingspecimenbeexaminedbyT.E.M?9MicroscopyToday:Transmissio94TransmissionElectronMicroscope10TransmissionElectronMicros95MicroscopyToday:ImmunofluorescenceLightMicroscopeAntibodiesdevelopedagainstaspecificproteinFluorescentdyemoleculeattachedtoantibodymoleculesSpecimenexposedtofluorescentantibodiesUltra-violetlight(blacklight)passedthroughspecimenFluorescentdyeglowsincolorwhereantigenislocatedEmittedlightisfocusedbyglasslensesontohumanretinaAllowsmappingdistributionofaspecificproteinincell11MicroscopyToday:Immunofluo96MicroscopyandAmoebaproteus12MicroscopyandAmoebaproteuCellsUndertheMicroscopephase-contrastlightmicroscope-lookatunstainedlivinganimalcells.electronmicroscope-lookatorganellese.g.ribosomes.fluorescencemicroscope-lookatalivingcellexpressinggreenfluorescentproteinortodoconfocalmicroscopy.CellsUndertheMicroscopephasAutoradiographyRadioactivecompoundsdecayortransformintoothercompoundsorelements.Anautoradiographisanimageonanx-rayfilmornuclearemulsionproducedbythepatternofdecayemissions(e.g.,betaparticlesorgammarays)fromadistributionofaradioactivesubstanceAutoradiographycanalsousesradioactivemoleculetostudybiochemicalactivity,Proteinsynthesis98AutoradiographyRadioactivecom99CellFractionationandDifferentialCentrifugationCellfractionationisthebreakingapartofcellularcomponentsDifferentialcentrifugation:AllowsseparationofcellpartsSeparatedoutbysize&densityWorkslikespincycleofwasherThefasterthemachinespins,thesmallerthepartsthataresettledout15CellFractionationandDiffe100CellFractionationandDifferentialCentrifugation16CellFractionationandDiffeEukaryotesVsProkaryotesEukaryoticCellsProkaryoticCellsThecellsof“complex”organisms,includingallplants,Protists,fungiandanimals“Simple”organisms,includingbacteriaandcyanobacteria(blue-greenalgae)ContainanucleusandmembraneboundorganellesLackanucleusandothermembrane-encasedorganelles.Canspecializeforcertainfunctions,suchasabsorbingnutrientsfromfoodortransmittingnerveimpulses;multicellularorgansandorganismsUsuallyexistassingle,virtuallyidenticalcellsCellWallpresentinPlantsandFungionlyRibosome:40s,60SCellWallRibosome:30S,50S101EukaryotesVsProkaryotesEukar102TheStructureofBacteriaOccurinthreebasicshapes:Sphericalcoccus,Rod-shapedbacillus,Spiralspirillum(ifrigid)orspirochete(ifflexible).CellEnvelopeincludes:Plasmamembrane-lipidbilayerwithimbeddedandperipheralproteinCellwall-maintainstheshapeofthecell18TheStructureofBacteriaOc103TheStructureofBacteria19TheStructureofBacteria104TheStructureofBacteria20TheStructureofBacteria105TheStructureofBacteriaCytoplasm&AppendagesCytoplasmSemifluidsolutionBoundedbyplasmamembraneContainswater,inorganicandorganicmolecules,andenzymes.Nucleoidisaregionthatcontainsthesingle,circularDNAmolecule.Plasmidsaresmallaccessory(extrachromosomal)ringsofDNAAppendagesFlagella–ProvidemotilityFimbriae–small,bristle-likefibersthatsproutfromthecellsurfaceSexpili–rigidtubularstructuresusedtopassDNAfromcelltocell21TheStructureofBacteriaCy106EukaryoticCellsDomainEukaryaincludes:ProtistsFungiPlantsAnimalsCellscontain:Membrane-boundnucleusthathousesDNASpecializedorganellesPlasmamembraneMuchlargerthanprokaryoticcellsSomecells(e.g.,plantcells)haveacellwall

22EukaryoticCellsDomainEukar107HypothesizedOriginofEukaryoticCells23HypothesizedOriginofEukar108EukaryoticCells:OrganellesEukaryoticcellsarecompartmentalizedTheycontainsmallstructurescalledorganellesPerformspecificfunctionsIsolatesreactionsfromothersTwoclassesoforganelles:Endomembranesystem:OrganellesthatcommunicatewithoneanotherViamembranechannelsViasmallvesiclesEnergyrelatedorganellesMitochondria&chloroplastsBasicallyindependent&self-sufficient24EukaryoticCells:Organelles109PlasmaMembrane25PlasmaMembrane110AnimalCellAnatomy26AnimalCellAnatomy111PlantCellAnatomy27PlantCellAnatomyCytosoleCytosol,containsmanylong,finefilamentsofproteinthatareresponsibleforcellshapeandstructureandtherebyformthecell’scytoskeleton112CytosoleCytosol,containsmany113NucleusCommandcenterofcell,usuallynearcenterSeparatedfromcytoplasmbynuclearenvelopeConsistsofdoublelayerofmembraneNuclearporespermitexchangebetweennucleoplasm&cytoplasmContainschromatininsemifluidnucleoplasmChromatincontainsDNAofgenes,andproteins(Histones)CondensestoformchromosomesChromosomesareformedduringcelldivisionNucleolusisadensestructureinthenucleusSynthesizeribosomeRNA(rRNA)29NucleusCommandcenterofcel114AnatomyoftheNucleus30AnatomyoftheNucleus115RibosomesArethesiteofproteinsynthesisinthecellComposedofrRNAandproteinConsistsofalargesubunitandasmallsubunitSubunitsmadeinnucleolusMaybelocated:Ontheendoplasmicreticulum(therebymakingit“rough”),orFreeinthecytoplasm31RibosomesArethesiteofpro116Nucleus,Ribosomes,&ER32Nucleus,Ribosomes,&ER117EndomembraneSystemSeriesofintracellularmembranesthatcompartmentalizethecellRestrictenzymaticreactionstospecificcompartmentswithincellConsistsof:NuclearenvelopeMembranesofendoplasmicreticulumGolgiapparatusVesiclesSeveraltypesTransportmaterialsbetweenorganellesofsystem33EndomembraneSystemSeriesof118EndomembraneSystem:

TheEndoplasmicRe