Question

In mitochondria, protons accumulate in

• A. Outer membrane
• B. Intermembrane space
• C. Inner membrane
• D. Matrix

Answer 1

The correct option is B Intermembrane space

In mitochondria, the inner membrane is impermeable to protons. Protons are pumped out of the inner membrane into the intermembrane space when electrons from reduced molecules pass through ETS. It is the back flow of protons through dedicated ion channels that is responsible for production of ATP.

So, the correct answer is 'Intermembrane space'.