For every one NADH molecule oxidized at complex I how many T

For every one NADH molecule oxidized at complex I, how many TOTAL hydrogen ions are pumped across all of the complexes from the mitochondrial matrix to the inner membrane space?

A:1

B:10

C:12

-An explanation would be appreciated!

Solution

Answer is B: NADH is the rich source of electron and it possess high reduction potential. So it transfer electrons (2e-) to oxygen through various complexes of Electron Transport Chain of Mitochondria. Those are Complex-I ----> Complex-III & Complex-IV. During electron transfer, 4:2:4 protons pumped form mitochondrial matrix to peri mitochondrial space via Complex-I, Complex-III & Complex-IV respectively