Question

Which of the following statements about photosynthesis is correct? (multiple answers may be correct) A: Carbon dioxide serves as final acceptor of high energy electrons provided by the light reactions B: Water serves only as an electron donor in oxygenic photosynthesis C: The oxygen released by oxygenic photosynthesis originates from water D: Hydrogen sulfide can also serve as electron donor in oxygenic photosynthesis E: in anoxygenic photosynthesis carbon dioxide does not serve as final electron acceptor.

Answer 1

Answer:

The correct statements are:

B: Water serves only as an electron donor in oxygenic photosyntheisis

C: The oxygen released by oxygenic photosynthesis originates from water

E: in anoxygenic photosynthesis, carbon dioxide does not serve as final electron acceptor.

Explanation:

• In oxygenic photosynthesis, the final high energy electron acceptor is NADP, hence statement 'A' is false.
• In oxygenic photosynthesis, water is split to generate electrons to reduce P680 back to its resting state, thus releasing oxygen in the process.Hence statement 'B' is true.
• Statement 'C' is also true, as oxygen is released when water molecule is split.
• Hydrogen sulfide generally serves as an good electron donor in anoxygenic photosynthesis. Hence, statement 'D' is false.
• unlike in oxygenic photosynthesis, where NADP is the final electron acceptor, no NADP is available in anoxygenic photosynthesis and electrons are cycled back into the system. Hence statement 'E' is true