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 $NADPH_2$ molecule
• D. 1 ATP and 2 $NADPH_2$ molecules

Answer 1

Answer: (B)

3 ATP and 2 $NADPH_2$ molecules

Answer 2

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