Question

Energy required to develop proton gradient during respiration comes from

• A. Oxidation process of $NADH$
• B. Oxidation-reduction process of $C{O}_2$ and $NADH$ respectively
• C. From heat energy developed during respiration
• D. Oxidation-reduction process of $NADPH$ and $O_2$ respectively

Answer 1

The correct option is A Oxidation process of $NADH$

When inside the mitochondria, pyruvate and fatty acids are broken down to acetyl CoA, which is then metabolized by the citric acid cycle. During the reaction, NAD${}^{+}$ is reduced to NADH. In the process of oxidative phosphorylation, high-energy electrons from NADH are passed along the ETC in the inner membrane to O${}_2$. This transport of electrons generates a proton gradient across the mitochondrial inner membrane, which drives the production of ATP by ATP synthase.

So, the correct option is 'Oxidation process of NADH'.