I EvergladesK-12 Florida ScienceStandardsBiology End-of-Course Chapter4 - Photosynthesis and CellularRespiration- SC.912.L.18.9 Photosynthesisand Cellular Respiration sc.912.t.18.9 Explainthe interrelated nature of photosynthesisand cellularrespiration. Alsoassesses: sc.g12.L.ra.7 ldentiS the reactants,products,and basic functionsof photosynthesis. sc.912.L.18.8 ldentiff the reactants,products,and basic functionsof aerobic and anaerobiccellular respiration. s c . 9 1 2 . 1 . 1 8 . 1 0 Connectthe role of adenosinetriphosphate (ATP)to energy transfers within a cell. To understandthe interrelatedprocesses of photosynthesis and cellular respiration,a discussionofenergy is required. First,energyis requiredfor life. Everyliving cell must receivea constantsupplyof energyin order for the cell to do its work. Second,energycan be transformed.Photosynthetic autotrophs use specificenergy wavelengthsfrom the electromagnetic spectrum. They transform this light energy into chemicalenergy. These specificwavelengthsare familiarto us as the wavelengthsof visiblelight. Scientists havestudiedthe responseof greenalgaeto differentgolorsof light from the specrum. Knowingthat oxygenis producedas a byproductof photosynthesis, it was discoveredthat the algaewere usingred or blue wavelengthsoflight to producethe oxygen.Pigmentsother than chloroohyll, carotenefor example,were studied,and it was discoveredthat different pigments utilize different light wavelengthsfor energizingthe photosynthetic process. Oncephotosynthesistraps the sun'senergyin sugarmolecules, this energy must be madeavailablefor cellsto do their work. (CertainArchaeabacteria usechemosynthesis for makingenergy-richmolecules.) r Cellular respiration releasesthe energy from sugar and stores that energyin a universalenergystoragemolecule,ATP. o AII cells utiliz" this moleculeand recycleit for energy storage. EvergladesK-12 Florida ScienceStandardsBiologyEnd-of-Course and CellularRespiration- SC.912.L.18.9 Chapter4 - Photosynthesis The ATP / ADP Cvcle high enerry phosphate bond ATP /\ @oo eners,+ @_______*@ _rn* ll----------ADP diphosphate ATP,adenosinetriphosphate, is madeup of adenine,ribose(a 5 carbonsugarl,and three phosphatemolecules. Visualizean adeninenucleotideof RNA,and you havea backboneof AMP,the singlephosphateform of the molecule. is connectedto a secondphosphatewith a highThis monophosphate energybond;the secondphosphateis connectedto a third phosphate with a secondhigh-energybond. When a cell requiresenergy,the third phosphateseparatesfrom ATP able and energyis released.The resultingmolecule,ADP,is recyclable, to acceptand storeenergyas ATP. An analogyoften usedis that ATP is Iike a rechargeablebattery. .r-_ --^_--_*?6"__-4 _-=-rr,_jb<(5 page 89 lt EvergladesK-12 Florida ScienceStandardsBiology End-of-Course Chapter4 - Photosynthesis and CellularRespiration- SC.912.t.19.9 Energyflows throughlivtngsystemsfrom producersto consumers.ATp can deliverchemicalenergyon demandfor the work of the cell. Someenergyis lost as heat;the rest is usedto power the needsof the cell,includingthe energy necessaryfor growth o The origin ofenergy for photosynthesizers [producersJand the energy they passto heterotrophscomesfrom the sun, o Producersare ableto transforntlight energyinto the chemicalenergy of glucose. o Producersand heterotrophsare ableto transformthe clremicalenergy storedin glucoseinto a 'currency,'theATP molecule.They per.fbrm this transformationin the processof cellularrespiration. Photosynthesis: Light Dependent Reactions Settingthe stagefor the first energy transformation from light energy to chemicalenergyrequiresthe chloroplast,the workspacefor photosynthesis. It is herethat the light dependent reactions of photosynthesis take place. Leafmesophyllcellstypicallyhavechloroplasts. r A membrane-bound organelle,the chloroplast's interior is packedwith stackedpancake-like menrbranesembeddedwith chlorophvll moleculesIresemblinglollipops). r Otherpigments,suchas carotene,canbe found in the membrarres. e Chlorophyllsand other pigmentscanabsorbslightlydifferentcolorsof light. Chlorophyllabsorbsred and blue light. o The stackedthylakoidmembranesare the sitesofthe light dependent reactlons. o The first raw materialrequiredfbr the light dependentreactionsis water. . Energyfrom sunlightenergizesa reactiveareain a pignrentmolecule, and this energyis usedto separatethe water moleculeinto oxygen, Ht fprotons]and e (electrons). . The oxygenof water is releasedinto the atmosphere. . Hydrogen'sprotonsmove throughand the electronsmove insidean electrontransportchainin the membranes. o As a result,ATP (light energytransformedinto chemicalenergyJis made,and the hydrogenatomswill be carriedto the light independent reactionsalonswith the ATP. page90 K-12FloridaScienceStandardsBiologyEnd-of-Course Everglades and CellularRespiration- SC.912.L.18.9 Chapter4 Photosynthesis Photosynthesis: Light lndependent Reactions The light independent reactions t:rl<eplacein the stronlainsidethe chloroplast,Thesereactionscanalsobe referredto as the Calvincycleor carbonfixation. o In smallcatall'zcdsteps,cafbondioxidefrom the atnrosphereis added rnolecirles, RUBISCO, onc of these to sugal b:rckbones to folnr giucc.rse e n z y l l r c sr s, t h e l n o s t , r b r r n r l l rpr r ot t e i no n E . l f t h . o The hydrogenneededto conlpletethe sugarmoleculeis deliveredto the stromaby the carrier molecLrle NADP. . ATP is dcliveredto providethe chemical From the light r€'actions, energyto svnthesizcthe sLrgalnrolecules. . This ATP r,villcontributea phosphatcand energyfrom a bond and recyclcb:ickto the light re:rctionsto be reenergized. fbr their-energyneeds.Since Greenplantsproduceglucoseby photosynthesis the transformedenergyfronr sunJightis storeclin strgarrnolecules, are ableto usegreenplantsfor therr energyneeds. heterotrophs,cor)sLurers The I n terrelationship BetweenPhotosynthesis and Respiration @-i Photosynthesjs Mitochondrion C e l l u l aR r espiration narrp Q1 EvergladesK-12 Florida ScienceStandardsBiology End-of-Course Chapter4 - Photosynthesisand Cellular Respiration- SC.912.L.18.9 Both autotrophsand lieterotrophsbreakdown the chernicalbondsof glucose and transferthe energyto ATP for later use. Cellularrespirationis the processby which this ATP is made. Respirationcan resultin a 2 ATPyield or a 36 ATPyield. . Glycolysis,a seriesof enzymaticallycatalyzedreactionsin the cytoplasm,producestwo 3-carbonmoleculesfrom glucose. o Glycolysisis believcdto be one of the mostancientof biochemical processes.Bacteriaget their energyfrom glycolysis. o Two moleculesof ATP are usedin this process,and four ATP molecules are nradelesultingin a net of Z ATP. Aerobiccellularrespirationcontinueswhen carbondioxideis releasedfrom a 3-carbonmoleculethat ts thetl rnovedinto a mitochondrionas a 2-carbon moleculewhere more ATPwill be made. . The mitochondrion is a membrane-bound organellepackedwith an inner doublemembraneand filledwith a liquid matrix. It is the site of the sequenceof the aerobicrespiratoryprocesses. o Carriedin by CoenzymeA, the 2-carbonsugarfragmentis movedinto the citric acid cyclefalsocalledthe KrebscycleJin the matrix. . ln this multi-enzymepathway,carbonand oxygenare removedas carbondioxidemolecules, someATP is made,and two carrier molecules, NAD aM FAD,pick up hydrogenatoms o Thesehydrogenatomsas H* and e-andsomegeneratedin glycolysis are movedto an electrontransportchain. o ATP will be madein the sameway as it was madein the light reactions of photosynthesis. o This shouldbe interestingto you. The oxygenthat you inhalewill combrnewith the hydrogen atoms to form water. You will exhalethis '"vateras vapor alongwith the carbondioxidebyproductproduced earlier. The ATP vield will be 36. \=:+a-+-t1: /---!q-at''+_ page9 2 EvergladesK-12 Florida ScienceStandardsBiology End-of-Course Chapter4 - Photosynthesis and CellularRespiration- SC.912.t.18.9 AnaerobicRespiration: LacticAcid and AlcoholicFermentation GLYCOLYSIS @ 2 N A D\ | Azsoe'ze ,NAD' f I \C*ilD t.- @ Noavailable oxygen @o ( l a c t i ca c i df e r m c nt a t i o n ) 2 g 1 6 2 n e+1 2 C O. [ a l r o h r -frel r m e nt a t i on ) The processcould havecontinuedin one of two directions. 1. A 3-carbonnroleculecan be convertedinto ethyl alcoholand carbon dioxide. o Yeastcellsand certainbactenacan carry out this conversionwith a yield of 2 ATP. o This is the anaerobic respiration known as alcoholic fermentatiqn. 2. A 3-carbonmoleculecanbe convertedinto lacticacid. o Our muscleceiisperfornrthis conversionwith a yield of 2 ATP. o This is an anaerobicprocessthat the musclerevertsto during heavy exerciseand in oxygen debt. This lactic acid fermentation, anotheranaerobicrespiration,is extremelyinefficient. The Chemical Summaries of Photosynthesis and Respiration Photosynthesis C^H,.O" t6O.{ 6CO. + 6H. O + energy(sunlight)------------> Respiration C 6 H , . 0 6* 6 0 , # 6CO.{ +6H.Of +energy(ATP) page 9J EvergladesK-12 Florida ScienceStandardsBiology End-of-Course Chapter4 - Photosynthesis and CellularRespiration- SC.912.L.18.9 To summarize,photosynthesis set of reactions,while is an energy-trapping cellularrespirationrs an energy-releasing set of reactions. o The origin of this energyis sunlight,but sunlightis transformedinto chemicalenergystoredin the ATP moleculeto power the light independent-glucose makingreactionsof photosynthesis. . The potentialchemicalenergyofglucoseis releasedin anaerobicor aerobicrespirationreactions,This energyis trappedin the ATP molecule. o ATP canbe usedwheneverthe cell needsenergy. o The raw materials(reactants]for photosynthesis are carbondioxide and water,and thesemoleculesare the productsof aerobicrespiration. o The productsof photosynthesis are sugar(glucose)and oxygen,and thesesamemoleculesare the reactantsfor aerobicresniration. Glucoseis the reactantfor anaerobicrespiration. o Photosynthetic reactionstake placein the chloroplast.Thesereactions includethe splittingof water that resultsin the releaseof oxygen. [Takea deepbreathl) o Cellularrespiratoryreactionsmay be confinedto glycolysisin the cytoplasm,rf anaerobic.Aerobicrespirationrequiresglycolysisand mitochondrialreactionsfin matrix and cristae). . Energyis requiredfor the photosyntheticprocess.The processof aerobicrespirationproducesenergyand storesit in 36 ATP molecules. o 2 ATP moleculesare producedby anaerobicrespiration,whether alcoholicfermentationor lacticacid fermentation r Alcoholicfermentationis a one-wayprocess;where as,lacticacid fermentationis reversible. ---__---./e- \4i*4b. pagev4 EvergladesK-12 Florida ScienceStandardsBiology End-of-Course and CellularRespiration- SC.912.L.18.9 Chapter4 - Photosynthesis Now Try These 1. ATP can changeits tnolecular identity into 2 other forms and recyclebackinto ATP. What are theseZ forms and how doeseach differ from ATP? 2. What are the ntolecular componentsof the ATP molecule? and in cellularrespiration' For 3 - 5, ATP is gcneratedin both photosynthesis as to thc ntakingand useofATP Completethe table Comparethe two processes below. Process Photosynthesis Chloroplast Respiration ls ATPrnadeasa final productor usedup in reactions? CellAreaor Organelle 3. 4. Anaerobic Respirationln the Cytoplasm Aerobic Respiration For 6 - 10, circlethe correctresponse f o r t h e f o l l o w i n gd, i s t i n g t t i s h i n g betweenaerobicand anaerobic respiratoryprocesses. 6. An anaerobicfermentationmay be by an end Productof characterized falcoholor water). J. ?. , CellularrespirationyieldsATP for [autotrophsand heterotrophsor heterotrophsonly). B. Aerobicrespirationrequiresthe reactionsof the (chloroPlast thyiakoidsand stromaor mitochondrionmatrix and cristaeJ. page9.r EvergladesK-12 Florida ScienceStandardsBiologyEnd-of-Course Chapter4 - Photosynthesisand Cellular Respiration- SC.912.L,18.9 9. Lacticacid fermentationcouldbe detectedin a fyeastcell or human rnusclecell). 10. In oxygendebt, certain cells can produceZ moleculesof ATP by (the electrbntransportchainor anaerobicfermentation). For l1 - 20, in order to be able to compareand contrastphotosynthesis and respiration,a basicunderstanding of the stepsof the processes, reactants,and productsis necessaly.Identifythe process,photosynthesis or respiration,for each orocessdescribedbelow. ProcessDescription 1 1 , Light Dependentand Light Independent processes take placein a chloroplast. 12. Aerobicprocessesare completedin a mitochondrion. 1 3 . An energy-richmoleculeis madefrom water and carbon dioxide. t4. Oxygenacceptinghyclrogenatoms formrngwateris the laststepin this process. Oxygenis a byproductof this processin autotroph s. 16. Alcohol,carbondioxide,and 2 ATPare made. Takea deepbreath. Oneprocessis producingthe oxyBer)you ale using. 36 ATP moleculesare productsof this proccss. Autotrophs carry,out andheterotrophs this process. Pigmentsthat canbe energizedare requiredfor this process. page96 Photosynthesis Respiration