All the dehydrogenases of glycolysis and the citric acid cycle use NAD+ (E'º for NAD+/NADH is −0.32 V) as electron acceptor except succinate dehydrogenase, which uses covalently-bound FAD (E'° for FAD/FADH₂ in this enzyme is 0.050 V). The E' value for fumarate/succinate is 0.031 V. Calculate the AG'° value for the oxidation of succinate using NAD+. AG'° = Calculate the AG'° value for the oxidation of succinate using covalently-bound FAD. AG'° = +67.55 -3.667 The kJ/mol kJ/mol Based on the E'° values of fumarate/succinate, NAD+/NADH, and the succinate dehydrogenase FAD/FADH2, why is FAD a more appropriate electron acceptor than NAD+ in the dehydrogenation of succinate? positive standard free-energy change favors the oxidation of succinate by covalently-bound FAD. This is consistent with K'eq = 1. Oxidation by NAD+ would require a large, negative standard free-energy change, with K'eq favoring the synthesis of succinate.

All the dehydrogenases of glycolysis and the citric acid cycle use NAD+ (E'º for NAD+/NADH is −0.32 V) as electron acceptor except succinate dehydrogenase, which uses covalently-bound FAD (E'° for FAD/FADH₂ in this enzyme is 0.050 V). The E' value for fumarate/succinate is 0.031 V. Calculate the AG'° value for the oxidation of succinate using NAD+. AG'° = Calculate the AG'° value for the oxidation of succinate using covalently-bound FAD. AG'° = +67.55 -3.667 The kJ/mol kJ/mol Based on the E'° values of fumarate/succinate, NAD+/NADH, and the succinate dehydrogenase FAD/FADH2, why is FAD a more appropriate electron acceptor than NAD+ in the dehydrogenation of succinate? positive standard free-energy change favors the oxidation of succinate by covalently-bound FAD. This is consistent with K'eq = 1. Oxidation by NAD+ would require a large, negative standard free-energy change, with K'eq favoring the synthesis of succinate.

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter20: Electron Transport And Oxidative Phosphorylation

Section: Chapter Questions

Problem 7P

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All the dehydrogenases of glycolysis and the citric acid cycle use NAD+ (?′°E′° for NAD+/NADH is −0.32 V−0.32 V) as electron acceptor except succinate dehydrogenase, which uses covalently‑bound FAD (?′°E′° for FAD/FADH2 in this enzyme is 0.050 V).0.050 V). The ?′°E′° value for fumarate/succinate is 0.031 V.0.031 V. a)Calculate the Δ?′°Δ⁢G′° value for the oxidation of succinate using NAD+. b)Calculate the Δ?′°Δ⁢G′° value for the oxidation of succinate using covalently‑bound FAD.