The Eight Reactions of the Krebs Cycle Process Diagrams Step-by-Step Copyright 2007 by John Wiley & Sons, Inc. 1 C CH 2 COOH O Oxaloacetic acid COOH Citric acid H2CH2CCOOH HOC H2CH2CCOOH + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain H2OH2O CO 2 NAD + KREBS CYCLE NADH CoA 1 C CH 2 COOH O Oxaloacetic acid COOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain H2OH2O CO 2 NAD + KREBS CYCLE NADH CoA 2 1 To electron transport chain CO 2 + H + C CH 2 COOH O Oxaloacetic acid COOH Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH NAD + + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain H2OH2O CO 2 NAD + KREBS CYCLE NADH CoA 2 3 O 1 To electron transport chain CO 2 + H + NADH CO 2 + H + C CH 2 COOH O Oxaloacetic acid COOH Succinyl CoA H2CH2CCOOH CH 2 CS CoA Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH NAD + + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain H2OH2O CO 2 NAD + KREBS CYCLE NADH O CoA O 2 3 4 1 To electron transport chain CO 2 + H + NADH CO 2 + H + C CH 2 COOH O Oxaloacetic acid COOH H2CH2C H2CH2C Succinic acid Succinyl CoA H2CH2CCOOH CH 2 CS CoA Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH NAD + GDP + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain ADP H2OH2O CO 2 NAD + KREBS CYCLE NADH ATP GTP O CoA O 1 To electron transport chain CO 2 + H + NADH CO 2 + H + To electron transport chain C CH 2 COOH O Oxaloacetic acid COOH H2CH2C H2CH2C Succinic acid Succinyl CoA H2CH2CCOOH CH 2 CS CoA Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH Fumaric acid NAD + GDP FAD HC CH + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain ADP FADH 2 COOH H2OH2O CO 2 NAD + KREBS CYCLE NADH ATP GTP CoA O O 1 To electron transport chain CO 2 + H + NADH CO 2 + H + To electron transport chain C CH 2 COOH O Oxaloacetic acid COOH HCOH CH 2 COOH H2CH2C H2CH2C Succinic acid Malic acid Succinyl CoA H2CH2CCOOH CH 2 CS CoA Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH Fumaric acid NAD + GDP FAD HC CH + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain ADP FADH 2 COOH H2OH2O H2OH2O CO 2 NAD + KREBS CYCLE NADH ATP GTP CoA O O 1 To electron transport chain CO 2 + H + NADH CO 2 + H + To electron transport chain C CH 2 COOH O Oxaloacetic acid COOH + H + NADH HCOH CH 2 COOH H2CH2C H2CH2C Succinic acid Malic acid Succinyl CoA H2CH2CCOOH CH 2 CS CoA Alpha-ketoglutaric acid H2CH2CCOOH HCH CCOOH Isocitric acid H2CH2CCOOH HOCCOOH HCCOOH H Citric acid H2CH2CCOOH HOC H2CH2CCOOH Fumaric acid NAD + GDP FAD NAD + HC CH + H + Pyruvic acid Acetyl coenzyme A C CH 3 O C COOH O To electron transport chain ADP FADH 2 COOH H2OH2O H2OH2O CO 2 NAD + KREBS CYCLE NADH ATP GTP CoA O O