Electron transport is coupled to ATP synthesis in mitochondria, in chloroplasts, and in thermophilic bacterium Methanococcus. Which of the following is likely to affect the coupling of the electron transport chain to ATP synthesis in all of these systems?

A) A potent inhibitor of cytochrome c oxidase
B) The removal of oxygen
C) The absence of light
D) An ADP analog that inhibits ATP synthase

I know that D is the correct answer but why? Could you please make it very detailed?

The correct answer is option D.

Explanation:

Each of the chemiosmotic coupling systems comprises a proton gradient, which is utilized by the enzyme ATP synthase to combine with ADP and phosphorylate it. Thus, any component that obstructs the binding of ATP with the synthase or that prevents the formation of the proton gradient will surely influence all the chemiosmotic systems.  

On the other hand, the element like oxygen and cytochrome c are needed only for aerobic bacteria and for mitochondria, they have no function in methanococcus, and light is needed only for the photosynthetic bacteria and for chloroplasts, and thus, have no role for methanococcus.  

the answer is:

carbon dioxide

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.