教程細(xì)胞生物學(xué)7.mitochondrion and peroxisone

morphologic:形態(tài)的proliferation:增7.1mitochondrialmorphologic7.2★mitochondrialstructureand7.3★targetingsignalandmitochondrialprotein7.4mitochondrialfunction---oxidative7.5mitochondrialproliferationand7.6peroxisome(過氧化物酶體In1890Altmann,bioblast(生物芽體in1898,Benda,in1900,Michaelis,siteofSummarizationoffunction:sensitive,organelle;oxidativecenterandpower (orenergytransducer)ATP（三磷酸腺苷 A—☆—ADP、semiautsemiautonomous半自性的compartmentalization:Summarizationofstructure:containnumberofinnermembranesfunction:scaffold;increasethemembranesurfaceofbiochemicalreaction;MitochondriapossessownDNAandproteinsyntheticsystem----semiautonomousorganelle7.1.2Mitochondrialmorphologyanddistribution1.Shape:(LM)granule,rod, hypotonicmedia:swellhypertonicmedia:shrink2.Size:diameter0.5-1um;length1.5-3.Number:dependonthetypesofcellphysiological4.distribution:random(livercell),activemetabolism---concentrationmitochondrialstructureandchemicalcomponentmitochondrioncontainsanoutermembraneandaninner

Matricalmitochondrial1、OuterUnitmembrane,thickness6-7nm,(光滑的)andcontinuousContainsporins(孔蛋白),diameter1-3nm,amolecularmasslessthan5000daltonscanpassly2、IntermembraneSpacebetweentheouterandinnermembrane,connectwithintracrisatespace(嵴內(nèi)腔),widthContainsmanysolubleproteinandThecompartmentmaychangewithactiveinvaginateinvaginateimpermeable:3、InnerMembraneandCristae(嵴innermembrane:5-6nm,unitinnnermembraneisinvaginatedintocristae(greatlyincreasetheamountofsurface)innermembraneishighlyimpermeable,virtuallyallmoleculesandionsrequirespecialmembranetransporterstogainentrancetothematrix

(嵴間腔Spacebetweencrisateandcrisatecontaingel-likeconsistency(稠度)-----matrix(基質(zhì))Matrixcontainsmitochondrialribosomes、double-strandcircularDNAandmatricalgranules(基質(zhì)顆粒)Matricalgranule:gatherCa2+、Mg2+andregulatetheinteriorioncircumstancemembraneStalkmembraneStalkHeadalayerofspheresattachtotheinnersideoftheinnermembrane（F0FHeadHeadsection(F1):8-10nm,composeoffivesubunits(3α3βγδε)/ function:synthesizeStalksection:OSCP(對(duì)寡霉素敏感的蛋白composeofγandεsubunitsregulateprotonMembranesection(F0):embededintheinnermembrane poseofthreesubunits/function:containachannelthroughwhichprotonsareconductedfromtheintermembranespacetothematrix7.2.3ChemicalComponentandProperty、chemical1.2.Protein:distributenumerouslyinsolubleproteinperipheralproteins、matricalinsolubleprotein----integral3.Lipid:phospholipid(75%),cholesterol(5%);richincardiolipinanddevoidofcholesterol(心磷脂monoamonoamine:單胺dehydrogenase:adenylate:1.Outermembraneenzyme(monoamineoxidasesynthesizingmitochondriallipid,degradingtryptophan(色氨酸)2.Intermembranespace(adenylate3.Innermembraneenzyme(cytochromeoxidase):respiratorychainenzymes,ATP-synthesizingenzyme,transportenzymes4.Matrixenzyme(malicaciddehydrogenase):tricarboxylicacidcycleenzymes,DNAandproteinsynthase.7.4MitochondrialFunction--Oxidative(氧化磷酸化Mitochondriaarethebaseofaerobicrespiration(有氧呼吸)andthesiteofprovidingenergy.Itprovides95percentoftheenergyofanaveragecell.Themaincharactersofmitochondriaareoxidatingeverysubstrateandconverting energyintoATPthatthecellscanutilizedirectlyCelloxidation(cellrespiration):Dependingonthecatalysisofenzymes,manysubstrateswithinthecellareoxidatedand posedby02,thenreleaseenergy,C02andH20.Becausetheprocessundergoeswithinthecellandexpends02,releasesC02andH20,alsocalledcellrespirationAnaerobic 1

2Aerobic

1

36-38Processofcellrespiration(cell③TCAcycle③TCAcycle②acetylCoA ）④④electrontransportand(innermembrane)酸Glycolysis(糖酵解1.fuels acidandfattyacids poseinthe 2.equation:23.Energy pyruvate酸acetylCoA:乙酰輔酶 ProduceAcetyl1.Pyruvateistransportedintomitochondrial2.equation:2pyruvate+2HS-CoA2AcetylCoA+23.Energytransfer:acetyl TheTricarboxylicAcid(TCA)AcetylAcetylReduced、electrontransportcouplesoxidativephosphorylation(innermembrane)(電子傳遞偶聯(lián)的氧化磷酸化 Electrontransportsintherespiratorychainrespiratorychain(electron-transportchain):aseriesofenzymeslocatedintheinnermitochondrialmembraneareorganizedintoHisdissociatedintoH+and electronpassalongthe chaingradually 1/202 reducedto02- isbound 2H+(matrix)toproduceH20Theelectronenergylevelfallsgradually.TheenergyreleasedfromelectronaretoATP，andthe

1/2O2istheterminalacceptorofelectronfrom1/2othersarebyheat

02istheterminalacceptorofelectronsfromtherespiratorychain7.4.3.Oxidativephosphorylation(氧化磷酸化ATPformationisdrivenbyenergythatisreleasedfromelectronsremovedduringsubstrateoxidation（伴隨電子傳遞鏈的氧chemiosmoticIn1961,PeterMitc ,chemiosmotictheory: transportcouplestheformationofATP. The precondition is that the innermitochondrial membrane remain highlyimpermeabletoprotonsandions,andformtheproton-motive force(). ProtonsmovedfromtheintermembranespacetomatrixcoupletheformationofATP:theenergyreleasedduringelectrontransportisstoredineletrochemicalgradient(電化學(xué)梯度)

formationofBindingchangemechanism(結(jié)合變構(gòu)機(jī)制,)：H+movementresultinthestructuralchangesofF1complex.ItmakesADPandPitobindactivesitecloselyandproduceTransporting pathway:singletransportproteins within the inner membrane

2

electron-transportand

22acetylCharacterofcell1.Containaseriesofoxidation-reductionreactionscatalyzedbyenzymeswithinthe2.Theenergyreleasedisstoredinthehigh-energyphosphateofATP3.Thewholereactionprogressesstepbystepandenergyreleasesstepbystep4.Reactionsundergounderconstanttemperatureandpressure5.Reactionsneed7.5MitochondrialproliferationandMitochondriapossesownDNAandthemachinerytomanufacturetheirRNAsandMtDNAonlyencodesasmallnumberofmitochondrialproteins.Moreover,amajorityofmitochondrialproteinsareencodedbygeneswithinthenucleus.1.mtDNAisadouble-strandedcircularDNA;replicatesthroughthewholecellcycle2.ProteinsinthemitochondrialribosomearealmostencodedbynuclearDNA3.Mitochondrialgeneticsystemalsodependsonthenucleargeneticsystem7.5.2mitochondriareproductiondependsonLeadingsignalandMitochondrialProteinOrientationProteinTargetingandtwotranslocationsof1、post-translationaltranslocation(翻譯后轉(zhuǎn)運(yùn)2、co-translationaltranslocation(共翻譯轉(zhuǎn)運(yùn)membrane-boundtransitpeptide:轉(zhuǎn)運(yùn)transitpeptide:轉(zhuǎn)運(yùn) Targetingsequence(導(dǎo)向序列proteinN-terminalsignalsynthesized proteinN-terminalsignalsynthesizedbymembrane-boundribosomeSignalpeptide(信號(hào)肽 LeadingPeptideleadingpeptide(前導(dǎo)肽):containanumberofpositivelychargedaminoacidresidues2080)intheproteinNterminalCharactersofleadingpeptidetransportingprotein:1.Need2.Enterfromcontactsite(接觸點(diǎn)3.Proteinsneed4.Need5Needtransitpeptidase(轉(zhuǎn)運(yùn)肽酶TranslocationofTranslocationofMatrix 1、preproteinsareunfoldedinthecyto preproteinisboundbyHSP70(cyto presentedinaunfolded2、preproteinstransportacrossmitochondrialmembraneleadingpeptidebindsreceptordirectspreproteinstoachannelformedbyoutermitochondrialmembraneproteinspreproteinspassthroughachannelformedbyinnermitochondrialmembraneproteins3、preproteinsarefoldedagainwithinthemitochondrialmatrixpreproteinsareboundbypreproteinsareboundbyHSP60andfoldathree-dimensionalstructureleadingpeptideiscutoffbytranslocationofmitochondrialintermembranespaceproteinsTwotargetingmatrix-targetingsequence(基質(zhì)導(dǎo)向序列intermembrane-space-targeting（膜間間隙導(dǎo)向序列2、nonconservativetargeting(非保守性尋靶translocationofmitochondrialinnermembraneproteins? TranslocationofOuterMembraneProteinsN-terminaltargetingsequenceisnotcutThefollowinghydrophobic eistoberegardedasstop-transfersequenceProteinsarefixedintheoutermembrane TOMcomplex(過氧化物酶體In1954membrane-boundgranuleslocatedinthecytosm(alsocalledTodaymicrobodyperoxisomeglyoxysome(乙醛酸循環(huán)體 morphologic1.shape,numberanddistributionShape:roundoroval,Φ0.1~1.7μm;containadensecrystallinecore(calledNumberlivercellandnephridialproximalconvolutedtubule(腎近曲小管)Dist