Chapter 12 (part 1) Citric Acid Cycle

Electron Transport and Oxidative phosphorylation Gylcolysis Electron Transport and Oxidative phosphorylation TCA Cycle

Entry into the TCA Cycle

Pyruvate Dehydrogenase

Citrate Synthase Only step in TCA cycle that involves the formation of a C-C bond

Aconitase

Isocitrate Dehydrogenase

 -Ketoglutarate Dehydrogenase

Succinyl-CoA Synthetase

Fumarase

Malate Dehydrogenase

Reduced Coenzymes Fuel ATP Production Acetyl-CoA + 3 NAD+ + Q + GDP + Pi +2 H20  HS-CoA + 3NADH + QH2 + GTP + 2 CO2 + 2 H+ Isocitrate Dehydrogenase 1 NADH=2.5 ATP a-ketoglutarate dehydrogenase 1 NADH=2.5 ATP Succinyl-CoA synthetase 1 GTP=1 ATP Sunccinate dehydrogenase 1 QH2=1.5 ATP Malate Dehydrogenase 1 NADH=2.5 ATP Total of 10 ATPs gained from oxidation of 1 Acetyl-CoA

Regulation of TCA Cycle

Protein/amino acid Catabolites feed Into the TCA Cycle

Fats breakdown and feed into the TCA Cycle

TCA Cycle provides intermediates for many biosynthetic processes

The Anaplerotic Reactions The "filling up" reactions PEP carboxylase - converts PEP to oxaloacetate Pyruvate carboxylase - converts pyruvate to oxaloacetate Malic enzyme converts pyruvate into malate

Following the carbons through the TCA cycle