Question

According to chemiosmotic theory of P. Mitchell (1978), ATPs are synthesised on membranes due to the

• A. Proton gradient
• B. Electron gradient
• C. Osmosis
• D. Diffusion

Answer 1

Answer: (A)

Proton gradient

According to chemiosmotic theory of Peter Mitchell, the transport of electrons across membranes is coupled to pumping of protons across the membranes, which establishes an electrochemical gradient. The electrochemical gradient of protons has an electrical component due to charge present on protons and a chemical component because of the hydrogen atom present in proton. Both the electrical and chemical gradients are used up to drive ATP synthesis by ATP synthase enzyme complex, when protons flow across the membranes through the ATP synthase enzyme system along the electrochemical gradient.