[Campbell Biology P.231] In cellular respiration and fermentation, what is the final electro... | Practice Question

In cellular respiration and fermentation, what is the final electron acceptor for NADH electrons during 1 fermentation, 2 aerobic respiration, and 3 anaerobic respiration, respectively?

  • A: (1) Pyruvate or an organic molecule; (2) O2; (3) an inorganic molecule other than O2.
  • B: (1) O2; (2) Pyruvate or an organic molecule; (3) an inorganic molecule other than O2.
  • C: (1) An inorganic molecule other than O2; (2) O2; (3) Pyruvate or an organic molecule.
  • D: (1) Pyruvate or an organic molecule; (2) an inorganic molecule other than O2; (3) O2.

Explanation

During fermentation, the final electron acceptor for NADH is an organic molecule, often pyruvate or a derivative. In aerobic respiration, oxygen O2 serves as the final electron acceptor. In anaerobic respiration, an inorganic molecule other than O2 e.g., nitrate or sulfate acts as the final electron acceptor.