Question

Why is the Calvin cycle considered a dark reaction?

Answer 1

It can proceed in the dark

Answer 2

The correct answer for this question is (D) It can proceed in the dark.

Calvin cycle is named after Melvin C. Calvin, who won a Nobel prize in chemistry for finding it in 1961. Calvin cycle take place in chloroplasts during photosynthesis and it is a light-independent reaction so also called as dark reaction.

The Calvin cycle proceeds in three stages:

1. Carboxylation, during which CO2 combines with ribulose-1,5- bisphosphate

2. Reduction, during which carbohydrate is formed at the expense of photochemically made ATP and NADPH

3. Regeneration during which the CO2 acceptor ribulose-1,5- bisphosphate is formed again so that the cycle continues.