Question

Fixation of one molecule of $CO_{2}$ through Calvin cycle requires

• A. 3 ATP and $3 NADPH _{2}$ molecules
• B. 3 ATP and $2 NADPH_{2}$ molecules
• C. 2 ATP and $1 NADPH_{2}$ molecules
• D. 1 ATP and $2 NADPH_{2}$ molecules

Answer 1

Answer: (B)

3 ATP and $2 NADPH_{2}$ molecules

Answer 2

Two ATP molecules are required during conversion of PGA to $1, 3$-diphosphoglyceric acid and one ATP molecule during conversion of glyceraldehyde phosphate to ribulose biphosphate. Two $NADH _{2}$ molecules are utilised for converting $1, 3$-diphosphoglyceric acid to glyceraldehyde phosphate.