Lecture 11 Notes - Cell Respiration
Lecture 11 Notes - Cell Respiration BIL 255
Popular in Cellular & Molecular Biology
Popular in Biology
This 5 page Class Notes was uploaded by Elizabeth Mompoint on Sunday October 18, 2015. The Class Notes belongs to BIL 255 at University of Miami taught by Dr. Mallery in Fall 2015. Since its upload, it has received 21 views. For similar materials see Cellular & Molecular Biology in Biology at University of Miami.
Reviews for Lecture 11 Notes - Cell Respiration
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 10/18/15
Cellular Energetics 3 Primary Molecular Mechanisms of ADP Phosphorylation 1 Cell and Molecular Biology Lecture 11 Molecularly cells make ATP mainly by phosphorylation of ADP cellularly its through organelle based processes in eukaryotes Heterotrophic Metabolism mitochondria cellular 39STNA EE 1239 BIFIIEJB DOWN 39D F F 00 D5 TD SIMlP LE SUBUNITS a 39 mxa 39 s s 7 umrs t cvmsot u39 p v z 17 I man BREAKDOWN as 3 1 SIMPLE sruuumns 7 10 am can Lm urea m owns 7 l or Mp AND mun ofeukaryatil IPRO we D Q respiration oxidation of foods anaerobic amp aerobic reactions 0 Substrate Level Phosphorylation O Oxidative Level Phosphorylation Autotrophic Metabolism chloroplast photosynthesis O Photophosphorylation STh GEis coMPLETE OXIDATION OF men L ton to H203 AND mi mm AMOUNTS or ATP IPRD DU CE D IN ero CH6 mzomon Substrate level phosphorylation transfer of P to ADP amp E3 l or GDP 0 s i 3 JD nhuep hnglweraaeiki39me 3 f I Pig an 2 F H Ef EIH H C DH EHd c CH9 1Exbisphosphoglwemte 3phosphuglywrane Chemiosmosis oxidative e capture leads to phosphorylation of ADP oxidation substH glu NADOX I NADHred product C02 H20 NADH e39transport I H proton motive force ATP synthase I ATP Photosynthetic phosphorylation sunlight provides energy to add P to ADP Light H20 NADP I NADPH e39 I H ATP synthase I ATP Cellular Respiration Heterotrophy or oxidation of food molecules to make ATP amp NADH Evolution of anaerobicaerobic metabolism was a major step in the history of life on planet Earth 3 stages 0 Digestion of food polymers CH20n I CH20 monomers 0 Production of AcoA via pyruvate I glycolysis ampor FAoxidation O Oxidation of AcoA to C02 amp H20 I Krebs Cycle amp Electron Transfer Chain 4 reaction systems of cellular respiration glucose oxidation of eukaryotes O A combination of anaerobic and aerobic metabolic pathways I Glycolysis cytoplasm glucose I pyruvate NADH ATP I Krebs Cycle mitochondria AcetylcoenzymeA I C02 H20 NADH GTP FADHZ I Electron Transport Chain ETC mitochondrial membranes passage of e s from NADHFADHZ to 02 I H20 H gradient I ATP synthase mitochondrial membrane mitochondrial membrane 24 subunit protein Which makes ATP as H move into mitoplasm With their chemical gradient Glycolysis The metabolic pathway which converts glucose via a series ANAEROBIC METABOLISM AEROBIC METABOLISMof GLYCOLYSIS KREBS CYCLE amp ETC reacuons to 2 111016011168 Of pyruvate39 substrate phosphorylation oxidative phosphorylation As a result of these reactions a small amount of ATP and mm magnum TD 0 NADH are produced I I Most of the metabolic energy derived from glucose comes GWWKmmmwmi the entry of pyruvate into the citric acid cycle and oxidative WMW MW I V 1 2 H30 7 Canesu 39 Transfer into F mm in r on El211 phosphorylation quot 39 m c m 399 39 These pathways occur under aerobic conditions 0 Overalilreactionof aembic metabolism GlucoseinGDRIwm ADP30 P a MDH id 39 converted to lactate 1n muscle or ethanol 1n yeast m mzmqmp m WW V 39ih39DS39 haryl ation Glycolys1s takes place 1n the cytoplasm of the cell 30 p agnwmm 39 39 39 39 i we 2 392aArpaazaIIao The goal of the 1n1t1al reactlons of glycolys1s 1s to Lgmgggmmswam m convert glucose into maw H F WmaM mmm mw Ifructose CHlEDH 1 6b1sphosphate v 0 0 The first step in H H0 977 W glycolysis is the phosphorylation of glucose OH by ATP to form EH mm glucose 6phosphate catalyzed by the enz me i STE 1quot hexokinase y Wl STEPS O The second step i gotta 0 min j a a on to fructose 6 OH phosphoglucose g 751 0 The third step is 1 sun 6biphosphate lm THO 10 step enzymatic g the isomerization of glucose 6phosphate I phosphate catalyzed by the enzyme quot7 somerase quot3 a second phosphorylation to form fructose 1 catalyzed by phosphofructokinase r pathway that converts CHO H CH DHI 1 LII20 ElmI20 g STEPS Minn 7 r if if hexose C6 I 4 51m PM 2 PYR C3 4 ATP 2 net 2 NADH Fates of NADH 1 STE 1 mitochondrial inner membrane is impervious to NADNADH W 77 l L Sg tim but an evolutionary advantage is shuttles moving e39s from the m mama cytoplasmic NADH39s into mitochondrial NADH or FADH2 CequotBlighmm gmm for eventual use in the ETC 0 glycerolP if V i V shuttle skeletal musclebrain O malate shuttle liver kidney heart muscle Summary of Glycolysis 0 2 ATP to initiate pathway 2 substrate level phosphorylations Makes 2 ATP net 2 NADH and 2 PYRUVATE anaerobic oxygen not required 0 O O 0 Fermentations lactate amp alcohol amp the Shuttles FEBMENITATlION IN YEAST regeneration W A Icohol idehy droge nase EC 1111 CH3 yeastplantsampbacterIa n I I II human liverllood alcohols Ram um EssentiaICell Eiolncw 41111 2M9 Earlaml Etienne 20111 0 NAD FERMEMTATION IN AN ACTIVE MUSCLE CELL quotAlf NAle H O O 0 NAD regeneration C H C E 0H Lactate dehydrogenase EC 1124 I CH3 Figure lBEa Essential Ell Nulng lll1 edjriiria amtl Salem 20114 KrebsCitric Acid Cycle A cyclical biochemical pathway resulting in aerobic oxidation of cellular fuels such as carbs fatty acids amp amino acids While making CO2 H20 amp ATP Localized in the mitochondria Overall reaction of Krebs s Cycle Acetyl CoA 3 NAD FAD GDP Pi 2 H20 I 2 C02 3 NADH FADHZ GTP H CoA The main point of entry for carbon molecules is as acetyl CoA 2C Which condenses With oxaloacetate 4C to form citrate 6C The citric acid cycle generates the reduced coenzymes NADH and FADH 2 as well as GTP The reduced coenzymes enter oxidative phosphorylation electron transfer chain Where the majority of the cell39s ATP is synthesized by the ATP synthase Enzymes of the cycle 0 5 dehydrogenases ISDH a KGDH SDH MDH amp PDH 2 hydratases aconitatse amp fumarase H20 1 thiokinase succinylCoA synthatase l synthetase citrate synthase 2 multienzyme complexes each With 60 proteins amp 5 coenzymes each I Pyruvate dehydrogenase I Alpha ketoglutarate dehydrogenase 0000 The complete citllic acid cycllc The two carbons 1mm accwl Con that exntcrthis turn of the cycle shadowed in rid lwill be converted to EU in aubaeuuem turns V 60 GlIa 2 C007 ngruuara ELJ U me rltioh 1221 or Ihe cycle il i5 Elm lwucarhons I EHFE395CQA 511 511an1111 in blue that are no nunn ml rn H5 COZ In this mle an x1 cycle C quot fr 0 IEDO m 7 quotmm T W COU39 u IU EHCOLI m Slap l s 2 Mm EOEquot cultacetate IIC 6H I w I l 30 cm E UL O r sums CH in am IGHJ um rrrr I IEEJ EDU HL39 COU H 0H oxnlnammotdC H CH tilll 1m are IdCl C00 CITRIC ACID C 39IULE V l H U U 9M 3 EOO quot lIJI39I39iafBl39E 39l39ICl okctuglumrmc 5E3 l 39 39 Step 391 Tml wwinvl cm Idol EH suwnalc C 600 le 5 Swp i 0 CLH H 11595 l 3 LI39l I rHl ml 5131 To me 39 1 S cm mm 393 2 9quot HS an 77 7 U l c cle rodu ctS39 2 ICrs Cm ll l3 acetyl CoA 6 NADH 2 FADH 2 GTP atp eq 39 4 CO cetate citrate 2 S STElFI 1 quot Emmet ase 39 39 STEP i messquot I 2 ll STEPS 2 g H STEM IO 2 oxaloa 2 ISDH Immarase STEP KW 23w r ingl SDH thiokinase 2 ll STEP 5 STEP 5 Elem H 27 A I39D 2 Figure 1311 Essential Cell Biology 2139s m 2004 Garland Science Pyruvate Dehydrogenase Complex catalyzes the Oxidative Decarboxylation of an alphaKeto acid Pyruvate CoA NAD I acetyl CoA C02 NADH O 3 enzymes 60 protein subunits I Pyruvate decarboxylase 0 12 dimers 24 identical subunits I Oxidatively decarboxylates the pyruvate by removing a CO I Lipoamide reductase transacetylase reductase I 8 trimers 24 identical subunits each 3 lipoates 0 Transfers the pyruvate carbon skeleton onto coenzymeA I Dihydrolipoyl dehydrogenase I 6 dimers 12 subunits With FAD Flam 0 Removes a hydrogen onto NAD making NADH O 5 coenzymes I CoASH I Lipoate I Thiamine pyrophosphate I EFAD I NAD Summary of Krebs Cycle 13 NMDPquot oxid lzed form oxidation of molecule 391 reduction of molecule 2 NDPa reduced form H I 1 t d or 9 mlnl lml a quotquot9 Ml l 39II x 39 5 1Fquot 11 I E i 1501 C307 I n thispllmsphaIe group I9 7 missing in NAD and NADH Ha mmmmmmemm1 1 Pyruvate is converted to acetyl CoA by the pyruvate dehydrogenase complex 2 The pyruvate dehydrogenase complex contains several enzyme activities and cofactors and is the key step regulating the ow of 2 carbon fragments into the citric acid cycle 9 Acetyl CoA condenses With oxaloacetate to form citrate as the first step of the Krebs cycle 4 One round 1 AcetylcoA of citric acid cycle results in the formation of 1 GTP 3 NADH 1 FADHZ and 2 C02 0 Fatty Acid Metabolism Oxidation of fatty acids triacylglycerol fatlipid droplet amp fatty acid Converts free fatty acids in blood into AcetylCoA in the mitochondria 3 steps of fatty acid oxidation cycle Beta Oxidation O Oxidation of COOH end of free fatty acid amp linking FFA to CoASH 0 Transport of fatty acylcoA into mitoplasm from cytoplasm O Oxidation of fatty acylcoA into 2 carbon fragments of AcetylCoA 4 enzymes 0 Long fatty acylcoA Synthetase converts cyotplasmic FFA to fattyacylcoA O Carnitine acylTransferase 1 transfers FAcoA to camitine for transport across mitochondria O Carnitine acylTransferase 2 releases carnitine amp leaves FAcoA inside the mitoplasm 0 Fatty acylcoA Dehydrogenase oxidizes FAcoA amp reduces FAD and NAD in 4 steps dietary fats free fatty acids MyIJCoAsynthetase fattyEcyICoA 1i Outer mitachnndriall Inner mitochondrial 7 membrane membrane quotlmiermemlhmneh I spate Matrix Carnitine alcyltranzst rase illl 39 SEu fattyacylCOA quot 39 A CoASIH Carnrtlne 39 Transporter Carmitine acy tramsferase ll 0 Step 4 of BetaOxidation Cycle Via fatty acylcoA dehydrogenase enzyme I dehydrogenation With FAD I FADH2 I hydration addition of water dehydrogenation With NAD I NADH thiol cleavage With CoASH Net result each turn of the cycle shortens a long chain fatty acid by 2 carbons generating 1 AcoA 1 NADH and 1 FADH2 for entry into Krebs cycle