Question

NADH and FADH${}_2$ carry high-energy electrons to the electron transport chain in cellular respiration. NADPH carries high-energy electrons to the electron transport chain in photosynthesis.
What are the terminal electron acceptors in the electron transport chain of cellular respiration and photosynthesis, respectively?

• A. Oxygen, NADP${}^{+}$
• B. Carbon dioxide, NAD${}^{+}$
• C. Oxygen, ATP
• D. Water, oxygen

Answer 1

The correct option is A Oxygen, NADP${}^{+}$

1. During cellular respiration, the electron transported through the series of co-enzymes and cytochromes is accepted by oxygen and thus becomes the terminal acceptor of the electron.
   
2. In photosynthesis, NADP is reduced to NADPH by accepting the electron from Photosystem1 (PS1). Thus becoming the terminal electron acceptor.