Question

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

• A. pH of the matrix increases
• B. $NA{D}^{+}$ is oxidised
• C. Cytochromes of the chain phosphorylate ADP to form ATP
• D. ATP synthase pumps protons by active transport

Answer 1

The correct option is D ATP synthase pumps protons by active transport

• Electron transport chain that is present in the mitochondria transports the electron from from the electron acceptor NADH and FADH from the inner membrane to the inter membrane matrix.
• As the amount of the hydronium ion in the inter membrane matrix increases the pH of the inter membrane matrix decreases.
• The ATP synthase complex which is present in the inner mitochondrial membrane transports the hydronium ions against its electrochemical gradient that is actice transport and for 2 hydronium ions transported one ATP is produced.
• Therefore the correct answer is option 'ATP synthase pumps protons by active transport'.