Which of the following combinations is required for chemiosmosis?
Answer: (A) membrane, proton pump, proton gradient, ATP synthase. Answer: (A) membrane, proton pump, proton gradient, ATP synthase.
- A.membrane, proton pump, proton gradient, ATP synthase✓
- B.membrane, proton pump, proton gradient, NADP synthase
- C.proton pump, electron gradient, ATP synthase
- D.proton pump, electron gradient, NADP synthase
Correct Answer
(A) membrane, proton pump, proton gradient, ATP synthase
Solution & Explanation
Answer: (A) membrane, proton pump, proton gradient, ATP synthase. Solution: Chemiosmosis requires a membrane (the inner mitochondrial membrane in respiration), a proton pump to push H+ across it building an electrochemical proton gradient, and ATP synthase (F0–F1 complex V) through which protons flow back, coupling the gradient to ATP synthesis. Options naming "NADP synthase" are wrong (no such enzyme works here; ATP is the product), and "electron gradient" is wrong — it is a PROTON gradient that drives the process. NCERT: Ch 12, p.161, line ~12: "The passage of protons through the channel is coupled to the catalytic site of the F1 component for the production of ATP".