Which of the following statements is incorrect?
- Oxidation-reduction reactions produce proton gradient in respiration
- During aerobic respiration, role of oxygen is limited to the terminal stage.
- In ETC (Electron Transport Chain), one molecule of NADH + H+ gives rise to 2 ATP molecules, and one FADH2 gives rise to 3 ATP molecules
- ATP is synthesized through complex V
Answer
(3) In ETC (Electron Transport Chain), one molecule of NADH + H+ gives rise to 2 ATP molecules, and one FADH2 gives rise to 3 ATP molecules
Solution
(1) Correct – as per NCERT, the oxidation-reduction reactions of the electron transport chain pump protons into the intermembrane space and produce a proton gradient.
(2) Correct – oxygen acts as the final hydrogen (electron) acceptor, so its role is limited to the terminal stage of aerobic respiration.
(3) Incorrect – as per NCERT, oxidation of one molecule of NADH + H+ gives rise to 3 ATP molecules, while one FADH2 gives rise to 2 ATP molecules; the statement interchanges the two values.
(4) Correct – ATP is synthesised by complex V (ATP synthase, F0–F1 particle).
∴ The incorrect statement is (3).
Answer: (3)