Chapter 10 The Citrate Cycle
10.1 The Citrate Cycle Captures Energy Using Redox Reactions Copyright © 2017 W. W. Norton & Company
Overview of the Citrate Cycle Copyright © 2017 W. W. Norton & Company
The Metabolic “Engine” Copyright © 2017 W. W. Norton & Company
10.2 Pyruvate Dehydrogenase Converts Pyruvate to Acetyl-CoA Copyright © 2017 W. W. Norton & Company
NAD+ and FAD Redox Reactions Common enzymes in oxidation–reduction reactions Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company Coenzyme A (CoA) Copyright © 2017 W. W. Norton & Company
Thiamine Pyrophosphate (TPP) Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company α-lipoic Acid Copyright © 2017 W. W. Norton & Company
Pyruvate Dehydrogenase Copyright © 2017 W. W. Norton & Company
Arsenic Inhibits Pyruvate Dehydrogenase Copyright © 2017 W. W. Norton & Company
10.3 Enzymatic Reactions of the Citrate Cycle Enzyme Standard free energy changes (kJ/mol) 1. acetyl-CoA plus Oxaloacetate plus upper H 2 upper O yields upper C-o upper A plus Citrate Citrate synthase Negative 31.4 2. Citrate is in equilibrium with Isocitrate Aconitase Plus 6.7 3. Isocitrate plus positive upper N upper A upper D ion yields alpha-Ketoglutarate plus upper N upper A upper D upper H plus upper C upper O 2 plus positive upper H ion. Isocitrate dehydrogenase Negative 20.9 4. alpha-Ketoglutarate plus upper C-o upper A plus positive upper N upper A upper D ion yields Succinyl-CoA plus upper N upper A upper D upper H plus upper C upper O 2 plus positive upper H ion. Alpha-Ketoglutarate dehydrogenase Negative 33.5 5. Succinyl-CoA plus GDP plus upper P-i is in equilibrium with Succinate plus GTP plus upper C-a upper A Succinyl-CoA synthase Negative 2.9 6. Succinate plus upper F upper A uppe D is in equilibrium with Fumarate plus upper F upper A upper D upper H 2. Succinate dehydrogenase Plus 0.4 7. Fumarate plus upper H 2 upper O is in equilibrium with Malate Fumarase Negative 3.8 8. Malate plus positive upper N upper A upper D ion is in equilibrium with Oxaloacetate plus upper N upper A upper D upper H plus positive upper H ion. Malate dehydrogenase Plus 29.3 Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company The Citrate Cycle Figure 10.21 The eight enzymatic reactions in the citrate cycle. Copyright © 2017 W. W. Norton & Company
The Citrate Cycle Animation Click to view the Citrate Cycle animation Copyright © 2017 W. W. Norton & Company
The Citrate Cycle (Step-by-Step) Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company Aconitase Copyright © 2017 W. W. Norton & Company
Isocitrate Dehydrogenase Copyright © 2017 W. W. Norton & Company
α-Ketoglutarate Dehydrogenase Copyright © 2017 W. W. Norton & Company
Succinyl-CoA Synthetase Copyright © 2017 W. W. Norton & Company
Succinate Dehydrogenase Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company Fumarase Copyright © 2017 W. W. Norton & Company
Copyright © 2017 W. W. Norton & Company Malate Dehydrogenase Copyright © 2017 W. W. Norton & Company
10.4 Regulation of the Citrate Cycle Copyright © 2017 W. W. Norton & Company
Control Points of the Citrate Cycle Copyright © 2017 W. W. Norton & Company
Feedback Inhibition in the Citrate Cycle Copyright © 2017 W. W. Norton & Company