1. Three Fates of Pyruvate Pyruvate  acetyl-CoA Occurs in mitochondria Produce CO 2 and NADH + H + Pyruvate Dehydrogenase Aerobic **Acetyl-CoA used in the TCA cycle

2. Three Fates of Pyruvate Pyruvate  Lactate Produce CO 2 and NAD + Homolactic fermentation Anaerobic Pyruvate  Ethanol Produce CO 2 and NAD + Alcoholic fermentation Anaerobic

3. Citric Acid Cycle 8 reactions Oxidize acetyl groups Acetyl groups come from many sources (not just carbohydrates) “Hub” of cellular metabolism Intermediates are precursors for the biosynthesis of other compounds 3 NAD + +FAD+GDP+P i +acetyl-CoA  3 NADH+FADH 2 +GTP+CoA+2 CO 2

4. Citric Acid Cycle Reaction 1 Oxaloacetate (OAA) + acetyl-CoA + H 2 O  Citrate + CoASH Citrate synthase Condensation Reaction 2 Citrate  Isocitrate Aconitase Isomerization

5. Citric Acid Cycle Reaction 3 Isocitrate + NAD +   Ketoglutarate (  KG) + NADH + H + + CO 2 Isocitrate dehydrogenase Dehydrogenation and oxidative decarboxylation Reaction 4  Ketoglutarate + CoASH + NAD +  Succinyl-CoA + NADH + H + + CO 2  Ketoglutarate dehydrogenase Dehydrogenation and oxidative decarboxylation

6. Citric Acid Cycle Reaction 5 Succinyl-CoA + GDP + P i  Succinate +GTP + CoASH Succinyl-CoA synthetase Substrate level phosphorylation via coupling reactions Reaction 6 Succinate + FAD  Fumarate + FADH 2 succinate dehydrogenase Dehydrogenation

7. Citric Acid Cycle Reaction 7 Fumarate + H 2 O  Malate Fumarase Hydration Reaction 8 Malate  Oxaloacetate Malate dehydrogenase Dehydrogenation

8. ATP Production NADH : ATP  1 : 3 FADH 2 : ATP  1 : 2 GTP : ATP  1 : 1

9. Summary of ATP Produced ProductsNet ATP Glycolysis -2 ATP +4 ATP +2 NADH+6 ATP PVA DH+2 NADH+6 ATP TCA cycle+6 NADH+18 ATP +2 FADH 2 +4 ATP +2 GTP+2 ATP Total38 ATP