Question

after electrons get excited by light a second time (at photosystem ii), where do they go? a. they travel down a second electron transport chain and are donated to nadp which becomes nadph (an electron carrier). b. they travel down a second electron transport chain and are donated to adp, which is then converted to atp. c. they remain excited and then travel to photosystem ii where they get even more excited until they spontaneously combust. d. they travel down a second electron transport chain and are donated to oxygen which then bonds to hydrogen ions to form water.

Explanation:

In photosynthesis, after electrons are excited a second - time at photosystem II, they travel down a second electron transport chain and are donated to NADP+ to form NADPH. This is a key step in the light - dependent reactions for the generation of energy - carrying molecules for the Calvin cycle. Options B, C, and D are incorrect as they do not accurately describe the electron flow. ADP is not the final electron acceptor here (B is wrong), electrons do not travel back to photosystem II to spontaneously combust (C is wrong), and oxygen is not the final electron acceptor in this context (D is wrong).

Answer:

A. They travel down a second electron transport chain and are donated to NADP which becomes NADPH (an electron carrier).