Question

How many molecules of ATP and NADPH are required for every molecule of CO₂ fixed in the Calvin cycle?

• A. 2 molecules of ATP and 3 molecules of NADPH
• B. 2 molecules of ATP and 2 molecules of NADPH
• C. 3 molecules of ATP and 3 molecules of NADPH
• D. 3 molecules of ATP and 2 molecules of NADPH

Answer 1

The Correct Option is D

Calvin Cycle: Carbon Fixation and Glucose Synthesis

The Calvin cycle performs carbon dioxide fixation and glucose synthesis.

Each carbon dioxide molecule fixed necessitates:

• 3 ATP molecules for cycle operation.
• 2 NADPH molecules for the reduction of 3-phosphoglycerate to glyceraldehyde-3-phosphate (G3P).

Consequently, 3 ATP molecules and 2 NADPH molecules are consumed per CO₂ fixed.