Answer:
b. Complex II
Explanation:
The electron transport chain is a sequential series of proteins located in the inner membrane of the mitochondria that act to transfer electrons from different members of the transport chain in a series of redox reactions, which is coupled to the movement of protons (H+) across the membrane. Complex I (also called NADH dehydrogenase or NADH- CoQ reductase) accepts electrons from NADH and passes them to Complex III (also known as coenzyme Q reductase), which also receives electrons from Complex II (succinate coenzyme Q reductase). Ubiquinone (Coenzyme Q) accepts electrons from both complex I and complex II and transfer them to complex III. From complex III electrons pass to complex IV through cytochrome c oxidase and finally to molecular oxygen (O2, the final electron acceptor). In consequence, Complex I and Complex II are linked by different pathways to Complex III, thereby it is expected that Complex II remains unaffected by a mutation in Complex I.
