Question

A total of ___ protons are translocated across the inner membrane of mitochondria per electron pair flowing from NADH to O2, whereas ___ protons are translocated per electron pair flowing from FADH2 to O2.

A. 30, 28
B. 10, 6
C. 2, 2
D. 4, 2

Answer 1

A total of 10 protons are translocated across the inner mitochondrial membrane per electron pair from NADH to O2, and 6 protons per electron pair from FADH2 to O2, making the answer B. 10, 6.

Step-by-step explanation:

A student has asked how many protons are translocated across the inner membrane of mitochondria per electron pair flowing from NADH and FADH2 to O2. The answer is that 10 protons are translocated per electron pair flowing from NADH to O2, while 6 protons are translocated per electron pair from FADH2 to O2. Therefore, the correct answer is B. 10, 6.

This translocation of protons is critical for creating a proton gradient that drives the synthesis of ATP by oxidative phosphorylation. Electrons from NADH enter at Complex I, while electrons from FADH2 enter the electron transport chain at Complex II, leading to a lower number of protons being pumped across the membrane in the latter case.