The reactions in complex II release very little free energy and do not contribute directly to the proton concentration gradient.

Question

Quizplus · Accepted Answer

Complex II, also known as succinate dehydrogenase, participates in the Krebs cycle by oxidizing succinate to fumarate and transferring electrons to coenzyme Q. This process releases a small amount of free energy but does not directly contribute to the generation of the proton gradient used for ATP synthesis. Instead, complex II indirectly contributes to the proton gradient by transferring electrons to coenzyme Q, which then participates in complex III and IV of the electron transport chain to generate a proton gradient.

The Reactions in Complex II Release Very Little Free Energy