Question

In Calvin cycle, the products of the light reaction (ATP and NADPH) are first utilized in the

• A. reduction step of the Calvin cycle
• B. regeneration step of the Calvin cycle
• C. carboxylation step of the Calvin cycle
• D. all of these

Answer 1

The correct option is A reduction step of the Calvin cycle

Calvin cycle takes place in the stroma of the chloroplast and is involved in the fixation of carbon dioxide molecules to synthesis glucose. The Calvin cycle includes three steps - carboxylation, reduction and regeneration.

The reduction step involves the use of two molecules of ATP for phosphorylation and two of NADPH.

The regeneration step in the Calvin cycle uses one ATP molecule for each RuBP molecule regenerated.

The carboxylation step does not involve the use of any ATP or NADPH molecule.