Anaerobic Respiration: The Definitive Guide | Biology Dictionary

Anaerobic respiration is the type of respiration through which cells can break down sugars to generate energy in the absence of oxygen. COVID-19TrackerTopicsBiologyA-ZCellBiochemistryHumanGeneticsZoologyBotanyEcologyAnatomy&PhysiologyMolecularMicrobiologyNeuroscienceArticlesAnimalKingdomTutorialsAPBiologyNGSSHighSchoolNews&StoriesLatestNewsEditors’PicksWeeklyDigestFunQuotesaboutBiologySearchSigninWelcome!LogintoyouraccountyourusernameyourpasswordForgotyourpassword?GethelpPrivacyPolicyPasswordrecoveryRecoveryourpasswordyouremailApasswordwillbee-mailedtoyou.BiologyDictionaryCOVID-19TrackerTopicsBiologyA-ZCellBiochemistryHumanGeneticsZoologyBotanyEcologyAnatomy&PhysiologyMolecularMicrobiologyNeuroscienceArticlesAnimalKingdomTutorialsAPBiologyNGSSHighSchoolNews&StoriesLatestNewsEditors’PicksWeeklyDigestFunQuotesaboutBiologyDefinitionOverviewAnaerobicvsAerobicRespirationSimilaritiesDifferencesCellularRespirationinDifferentOrganismsEquationsExamplesSoreMusclesandLacticAcidYeastsandAlcoholicDrinksMethanogenesisandDangerousHomebrewsSwissCheeseandPropionicAcidVinegarandAcetogenesisQuizIndexCOVID-19TrackerTopicsBiologyA-ZArticlesAnimalKingdomTutorialsAPBiologyNGSSHighSchoolNews&StoriesLatestNewsEditors’PicksWeeklyDigestBiology4FunQuotesFollowUsSubscribetoOurNewsletterLeavethisfieldemptyifyou'rehuman:AnaerobicRespirationBy:KatyMcLaughlin,Ph.D.Reviewedby:BDEditorsLastUpdated:October23,2020DefinitionAnaerobicrespirationisthetypeofrespirationthroughwhichcellscanbreakdownsugarstogenerateenergyintheabsenceofoxygen.Thisisincontrasttothehighlyefficientprocessofaerobicrespiration,whichreliesonoxygentoproduceenergy.Molecularoxygenisthemostefficientelectronacceptorforrespiration,duetoitshighaffinityforelectrons.However,someorganismshaveevolvedtouseotherfinalelectronacceptors,andassuch,canperformrespirationwithoutoxygen.AnaerobicrespirationOverviewRespirationistheprocessthroughwhichtheenergystoredinfuelisconvertedintoaformthatacellcanuse.Typically,energystoredinthemolecularbondsofasugarorfatmoleculeisusedtomakeATP,bytakingelectronsfromthefuelmoleculeandusingthemtopoweranelectrontransportchain.Respirationiscrucialtoacell’ssurvivalbecauseifitcannotliberateenergyfromfuels,itwillnothavesufficientenergytodriveitsnormalfunctions.Thisiswhyair-breathingorganismsdiesoquicklywithoutaconstantsupplyofoxygen:ourcellscannotgenerateenoughenergytostayalivewithoutit.Insteadofoxygen,anaerobiccellsusesubstancessuchassulfate,nitrate,sulfur,andfumaratetodrivetheircellularrespiration.Manycellscanperformeitheraerobicoranaerobicrespiration,dependingonwhetheroxygenisavailable.AnaerobicvsAerobicRespirationSimilaritiesBothaerobicandanaerobicrespirationaremethodsofharvestingenergyfromafoodsource,suchasfatsorsugars.Bothprocessesbeginwiththesplittingofasix-carbonsugarmoleculeinto2three-carbonpyruvatemoleculesinaprocesscalledglycolysis.ThisprocessconsumestwoATPmoleculesandcreatesfourATP,foranetgainoftwoATPpersugarmoleculethatissplit.Inbothaerobicandanaerobicrespiration,thetwopyruvatemoleculesaresubjecttoanotherseriesofreactionsthatuseelectrontransportchainstogeneratemoreATP.Itisthesereactionsthatrequireanelectronacceptor–beitoxygen,sulfate,nitrate,etc.– inordertodrivethem.Manybacteriaandarchaeacanonlyperformanaerobicrespiration.Manyotherorganismscanperformeitheraerobicoranaerobicrespiration,dependingonwhetheroxygenispresent.Humansandotheranimalsrelyonaerobicrespirationtostayalive,butcanextendtheircells’livesorperformanceintheabsenceofoxygenthroughanaerobicrespiration.DifferencesAfterglycolysis,boththeaerobicandanaerobiccellssendthetwopyruvatemoleculesthroughaseriesofchemicalreactionstogeneratemoreATPandextractelectronsforuseintheirelectrontransportchain.However,whatthesereactionsare,andwheretheyhappen,variesbetweenaerobicandanaerobicrespirationDuringaerobicrespiration,theelectrontransportchain,andmostofthechemicalreactionsofrespiration,occurinthemitochondria.Themitochondria’ssystemofmembranesmakestheprocessmuchmoreefficientbyconcentratingthechemicalreactantsofrespirationtogetherinonesmallspace.Incontrast,anaerobicrespirationtypicallytakesplaceinthecytoplasm.Thisisbecausemostcellsthatexclusivelycarryoutanaerobicrespirationdonothavespecializedorganelles.Theseriesofreactionsistypicallyshorterinanaerobicrespirationandusesafinalelectronacceptorsuchassulfate,nitrate,sulfur,orfumarateinsteadofoxygen.AnaerobicrespirationalsoproduceslessATPforeachsugarmoleculedigestedthanaerobicrespiration,makingitalessefficientmethodofgeneratingcellularenergy.Inaddition,itproducesdifferentwasteproducts–including,insomecases,alcohol!Aerobicallydifferentbacteriabehavedifferentlywhengrowninthioglycolatebroth.1.Obligateaerobicbacteriagatheratthetopofthetesttubeinordertogetaccesstooxygen.2.Obligateanaerobicbacteriacollectatthebottomtoavoidoxygenfromthetop.3.Facultativebacteriagathermostlyatthetopsinceaerobicrespirationismostefficient,butsincetheycansurvivewithalackofoxygen,theycanbefoundthroughouttheculture.4.Microaerophilesgatherattheupperpartofthetesttubebutnotatthetop.Theyrequireoxygenbutarepoisonedbyhighconcentrationsofoxygen.5.Aerotolerantorganismsarenotaffectedatallbyoxygen,andtheyareevenlyspreadalongthetesttube.CellularRespirationinDifferentOrganismsOrganismscanbeclassifiedbasedonthetypesofcellularrespirationtheycarryout.Obligateaerobes–organismsthatcannotsurvivewithoutoxygen.Forexample,humansareobligateaerobes.Obligateanaerobes–organismsthatcannotsurviveinthepresenceofoxygen.Certainspeciesofbacteriaareobligateanaerobes,suchasClostridiumtetani, whichcausestetanus.Aerotolerantorganisms–organismsthatcanliveinthepresenceofoxygen,butdoesnotuseittogrow.Forexample,thebacteriumStreptococcus,whichcausesStrepthroat.Facultativeaerobes–organismsthatcanuseoxygentogrow,butcanalsoperformanaerobicrespiration.Forexample,Saccharomycescerevisiae whichistheyeastusedinbrewing.Scientistscanclassifymicrobesinthiswayusingasimpleexperimentalset-upwiththioglycolatebroth.Thismediumcontainsarangeofoxygenconcentrations,producingagradient.Thisisbecauseofthepresenceofsodiumthioglycolate,whichconsumesoxygen,andthecontinuoussupplyofoxygenfromtheair;atthetopofthetube,oxygenwillbepresent,andatthebottom,nooxygenwillbepresent.TypesofAnaerobicRespirationThetypesofanaerobicrespirationareasvariedasitselectronacceptors.Importanttypesofanaerobicrespirationinclude:Lacticacidfermentation–Inthistypeofanaerobicrespiration,glucoseissplitintotwomoleculesoflacticacidtoproducetwoATP.Itoccursincertaintypesofbacteriaandsomeanimaltissues,suchasmusclecellsAlcoholicfermentation–Inthistypeofanaerobicrespiration,glucoseissplitintoethanolorethylalcohol.ThisprocessalsoproducestwoATPpersugarmolecule.Thisoccursinyeastandeveninsometypesoffish,suchasgoldfish.Othertypesoffermentation–Othertypesoffermentationareperformedbysomebacteriaandarchaea.Theseincludepropionicacidfermentation,butyricacidfermentation,solventfermentation,mixedacidfermentation,butanediolfermentation,Sticklandfermentation,acetogenesis,andmethanogenesis.AnaerobicRespirationEquationsTheequationsforthetwomostcommontypesofanaerobicrespirationare:•Lacticacidfermentation:C6H12O6(glucose)+2ADP+2pi→2lacticacid+2ATP•Alcoholicfermentation:C6H12O6(glucose)+2ADP+2pi→2C2H5OH(ethanol)+2CO2+2ATPExamplesofAnaerobicRespirationSoreMusclesandLacticAcidDuringintenseexercise,ourmusclesuseoxygentoproduceATPfasterthanwecansupplyit.Whenthishappens,musclecellscanperformglycolysisfasterthantheycansupplyoxygentothemitochondrialelectrontransportchain.Theresultisthatanaerobicrespirationandlacticacidfermentationoccurswithinourcells–andafterprolongedexercise,thebuilt-uplacticacidcanmakeourmusclessore!YeastsandAlcoholicDrinksBeerfermentationreliesonethanolfermentationbyyeast.Alcoholicdrinkssuchaswineandwhiskeyaretypicallyproducedbybottlingyeasts–whichperformalcoholicfermentation–withasolutionofsugarandotherflavoringcompounds.Yeastscanusecomplexcarbohydratesincludingthosefoundinpotatoes,grapes,corn,andmanyothergrains,assourcesofsugartocarryoutcellularrespiration.Puttingtheyeastanditsfuelsourceinanairtightbottleensuresthattherewillnotbeenoughoxygenaround,andthustheyeastwillconverttoanaerobicrespiration.Thisproducesalcohol.Alcoholisactuallytoxictotheyeaststhatproduceit–whenalcoholconcentrationsbecomehighenough,theyeastwillbegintodie.Forthatreason,itisnotpossibletobrewwineorabeerthathasgreaterthan30%alcoholcontent.However,theprocessofdistillation,whichseparatesalcoholfromothercomponentsofthebrew,canbeusedtoconcentratethealcoholandproducespiritssuchasvodka.MethanogenesisandDangerousHomebrewsUnfortunately,alcoholicfermentationisn’ttheonlykindoffermentationthatcanhappeninplantmatter.Adifferentalcohol,calledmethanol,canbeproducedfromthefermentationofcellulose.Thiscancausemethanolpoisoning.Thedangersof“moonshine”–cheap,homebrewedalcoholwhichoftencontainshighamountsofmethanolduetopoorbrewinganddistillationprocesses–wereadvertisedinthe20thcenturyduringprohibition.Deathandnervedamagefrommethanolpoisoningisstillanissueinareaswherepeopletrytobrewalcoholcheaply.So,ifyou’regoingtobecomeabrewer,makesureyoudoyourhomework!SwissCheeseandPropionicAcidPropionicacidfermentationgivesSwisscheeseitsdistinctiveflavor.TheholesinSwisscheeseareactuallymadebybubblesofcarbondioxidegasreleasedasawasteproductofabacteriathatusespropionicacidfermentation.TheholesinSwisscheesecomefromanaerobicrespirationAftertheimplementationofstrictersanitationstandardsinthe20thcentury,manyproducersofSwisscheesewerepuzzledtofindthattheircheesewaslosingitsholes–anditsflavor.Theculpritwasdiscoveredtobealackofaspecificbacteriawhichproducepropionicacid.Throughouttheages,thisbacteriahadbeenintroducedasacontaminantfromthehaythecowsate.Butafterstricterhygienestandardswereintroduced,thiswasnothappeninganymore!ThisbacteriaisnowaddedintentionallyduringproductiontoensurethatSwisscheesestaysflavorfulandretainsitsinstantlyrecognizableholeyappearance.VinegarandAcetogenesisBacteriathatperformacetogenesisareresponsibleforthemakingofvinegar,whichconsistsmainlyofaceticacid.Vinegaractuallyrequirestwofermentationprocesses,becausethebacteriathatmakeaceticacidrequirealcoholasfuel!Assuch,vinegarisfirstfermentedintoanalcoholicpreparation,suchaswine.Thealcoholicmixtureisthenfermentedagainusingtheacetogenicbacteria.Quiz1.AllcellsperformglycolysisA.TrueB.False2.WhichoftheseisNOTatypeofanaerobicrespiration?A.LacticacidfermentationB.AlcoholicfermentationC.OxidativephosphorylationD.Propionicacidfermentation3.Whatareobligateanaerobes?A.OrganismsthatcanswitchbetweenaerobicandanaerobicrespirationB.OrganismsthatcannotsurviveintheabsenceofoxygenC.OrganismsthatcannotsurviveinthepresenceofoxygenD.OrganismsthatcanuseoxygenforrespirationbutdonotalwaysEnteryouremailtoreceiveresults: Loading... BibliographyShow/HideBerg,J.M.,Tymoczko,J.L.,Stryer,L.Biochemistry.5thedition.NewYork:WHFreeman;2002.Section18.6,TheRegulationofCellularRespirationIsGovernedPrimarilybytheNeedforATP.Availablefrom:https://www.ncbi.nlm.nih.gov/books/NBK22448/Alberts,B.,Johnson,A.,Lewis,J.,etal.MolecularBiologyoftheCell.4thedition.NewYork:GarlandScience;2002.References. Availablefrom:https://www.ncbi.nlm.nih.gov/books/NBK26903/Jurtshuk,P.Jr.BacterialMetabolism.In:MedicalMicrobiology.4thedition.Galveston(TX):UniversityofTexasMedicalBranchatGalveston;1996.Chapter4. Availablefrom:https://www.ncbi.nlm.nih.gov/books/NBK7919/Lodish,H.,Berk,A.,Zipursky,S.L.,etal.MolecularCellBiology.4thedition.NewYork:W.H.Freeman;2000.Availablefrom:https://www.ncbi.nlm.nih.gov/books/NBK21475/CiteThisArticleMLAAPAChicagoBiologydictionary.netEditors."AnaerobicRespiration."BiologyDictionary,Biologydictionary.net,27Oct.2016,https://biologydictionary.net/anaerobic-respiration/.Biologydictionary.netEditors.(2016,October27).AnaerobicRespiration.Retrievedfromhttps://biologydictionary.net/anaerobic-respiration/Biologydictionary.netEditors."AnaerobicRespiration."BiologyDictionary.Biologydictionary.net,October27,2016.https://biologydictionary.net/anaerobic-respiration/.SubscribetoOurNewsletterLeavethisfieldemptyifyou'rehuman: AboutAboutDecember18,2016CareersMay2,2019OurTeamMay2,2019ContactOctober14,2016PrivacyPolicyOctober14,2016TermsofServiceOctober14,2016ScholarshipMay13,2017CitationOctober14,2016LatestPostsAdipocyteJune15,2021WhiteBloodCellJune9,2021BasalCellMay31,2021BloodCellMay30,2021TCellImmunityMay26,2021SatelliteCellsMay23,2021EmbryonicStemCellsMay20,2021HeLaCellsMay15,2021PopularTopicsDNAMay27,2017HermaphroditeDecember9,2016HomeostasisOctober29,2016HeartJuly26,2017CommunityDecember29,2016TranslationNovember23,2016CellNovember15,2016MeiosisDecember9,2016ABOUTUSThedefinitivesourceofmeaningfulandinformativeexplanationsofbiologicalconcepts.Contactus:[email protected]©2022BiologyDictionary.AllRightsReserved.