IMAT 2021 Q34 [Chloroplast]

In which of the following places are proton pumps found?

1 the chloroplast stroma
2 the gap between the thylakoid membranes
3 the membrane of the granum

A 3 only
B 2 only
C 1 only
D 1 and 2 only
E 1 and 3 only

Answer should be A, right?

it’s because proton pumps (enzymes that produce ATP) are part of the electron transport chain found in chloroplasts (and mitochondria). In chloroplasts, the electron transport chain is located on the thylakoid membrane. The Granum is a stack of thylakoids, so it’s membrane is the thylakoids’ membrane, making it the only correct answer, as the ETC cannot exist in the stroma of the chloroplast.

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Thank you!! I also realized that proton pumps can only be located on membrane, so that eliminates other options