Question

What will most likely happen if the hydrogen pump protein in photosystem II doesn't take in enough H⁺ ions into the thylakoid?

a. there will be a decrease in light absorption by chlorophyll
b. there will be an increase in glucose production
c. there will be a decrease in the formation of ATP
d. there will be an increase in CO₂ absorption by the chloroplast.

Answer 1

c. there will be a decrease in the formation of ATP

Step-by-step explanation:

During the light-dependent phase of photosynthesis, electrons move from PS-II to the electron carriers embedded in the thylakoid membrane. During this process of electron transfer from PS-II to the intermediate carriers, protons are pumped from the stroma to the thylakoid space. The resultant proton concentration gradient drives the facilitated diffusion of protons through the proton channels of ATP synthase and phosphorylation of ADP into ATP.

If sufficient protons are not pumped through the hydrogen pump, the proton concentration gradient would not be steep and the ATP synthesis would be reduced.