Which of the following could be TRUE if a plant cell is exposed to a toxin that makes the thylakoid membrane freely permeable to protons?
A)There would be no ATP available to drive carbohydrate synthesis in the Calvin cycle.
B)There would be no ATP needed to split water molecules early in the light-dependent pathway.
C)There would be no ATP produced in the chloroplasts to power photosynthesis in the absence of light energy.
D)ATP generated by the mitochondria would be used to power photosynthesis, so plant cells would not have enough ATP left to supply the many other processes that require it.
E)The amount of NADPH in the chloroplast would increase.

Question

Quizplus · Accepted Answer

If the thylakoid membrane is freely permeable to protons, then the proton gradient that is normally used to drive ATP synthesis will be dissipated. This means that there will be no ATP available to drive carbohydrate synthesis in the Calvin cycle (A). However, the splitting of water molecules early in the light-dependent pathway does not require ATP (B). In the absence of light energy, there will be no ATP produced in the chloroplasts to power photosynthesis (C). The mitochondria will not be able to generate enough ATP to power photosynthesis and supply the many other processes that require it (D). The amount of NADPH in the chloroplast will increase because the electrons that are normally used to reduce NADP+ will not be able to be used to generate ATP (E).

Which of the Following Could Be TRUE If a Plant