For the conversion of succinate to fumarate, the standard reduction potentials (
ID: 1064811 • Letter: F
Question
For the conversion of succinate to fumarate, the standard reduction potentials (E' degree) for the following half reactions are given. Fumarate + 2H^+ + 2e^- reversiblearrow succinate E' degree = +0.031 V FAD + 2H^+ + 2e^reversiblearrow FADH_2 E' degree = -0.219 V If you mixed succinate, fumarate, FAD, and FADH_2 together, all at 1 M concentrations and in the presence of succinate dehydrogenase, which of the following would happen initially? Fumarate and succinate would become oxidized; FAD and FADH_2 would become reduced. Fumarate would become reduced; FADH_2 would become oxidized. No reaction would occur because all reactants and products are already at their standard concentrations. Succinate would become oxidized; FAD would become reduced. Succinate would become oxidized; FADH_2 would be unchanged because it is a cofactor.Explanation / Answer
The given standard reduction potentials are
Fumarate + 2H+ + 2e- -------> succinate E0 = +0.031V
FAD + 2H+ + 2e- ---------> FADH2 E0 = -0.219V
Reduction potential of FAD to FADH2 is in negative value , so it will not favor.But reduction potential of fumarate to succinate is positive , so this reaction will favor. So the answer is fumarate would become reduced to succinate and FADH2 is oxidised to FAD.