Question

In electron transport system in the inner mitochondria membrane, complexes I and IV are respectively

• A. NADH dehydrogenase and FADH${}_2$
• B. NADH${}_2$ and NADH dehydrogenase
• C. NADH dehydrogenase and cytochrome-c oxidase
• D. NADH dehydrogenase and ATP synthase

Answer 1

Answer: (C)

NADH dehydrogenase and cytochrome-c oxidase

In the inner membrane of the mitochondria, electrons from NADH and FADH${}_2$ go through the electron transport chain and are transferred to oxygen, which is reduced to H${}_2$$O$. The electron transport chain consists of an enzymatic arrangement of electron donors and acceptors. It includes various electron carriers like complex I, complex Q, complex II, complex III, cytochrome c and complex IV.

Complex I - NADH dehydrogenase or NADH-coenzyme Q reductase.

Complex II - Succinate dehydrogenase or Succinate-CoQ reductase.

Complex III - Coenzyme-Q reductase.

Complex IV - Cytochrome-c oxidase.

So, the correct answer is option C.