Question

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from?

Answer 1

The question is incomplete as it does not have the options which are:

A) photosystem II

B) photosystem I

C) cyclic electron flow

D) linear electron flow

E) chlorophyll

Answer:Cyclic electron flow

Explanation:

The plants produce ATP molecule by the process of a light-dependent phase of photosynthesis which produces ATP and NADPH molecules.

The ATP and NADPH are produced by the non-cyclic flow of electrons called Z-scheme but when the plant needs extra ATP molecules, they produce more ATP by the cyclic electron flow.

The cyclic electron flow begins when the P₇₀₀ activates electron which then transferred to ferredoxin and then to cyt b₆f and then to plastocyanin. This is repeated and produce ATP molecules escaping the production of NADPH.

Thus, Cyclic electron flow is correct.