Question

Which among these pumps protons to the mitochondrial intermembrane space?

• A. Ubiquinone
• B. NADH Dehydrogenase complex
• C. Cytochrome Oxidase complex
• D. Both B and C

Answer 1

The correct option is D Both B and C

Proton translocation is an important part of the electron transport system in which the electron passes through two complexes and series of electron carriers. NADH dehydrogenase Complex and cytochrome oxidase complex are responsible for pumping these protons outside the mitochondrial membrane. The ubiquinone is a mobile element that is responsible for the transport of the electron from one complex to another but it does not have a specialised mechanism to pump proton outside into a mitochondrial membrane.

So, the correct option is 'Both B and C'