Question

In addition to the $12$ molecules of $NADPH$ the energy required for the synthesis of one mole of hexose by $C_3$ and $C_4$ pathway is

• A. 18 molecules of ATP
• B. 30 molecules of ATP
• C. 18 and 30 molecules of ATP respectively
• D. 30 and 18 molecules of ATP respectively

Answer 1

The correct option is C 18 and 30 molecules of ATP respectively

To make one glucose molecule (fix $6C{O}_2)$ in Calvin cycle or C3 pathway required six turns of Calvin cycle -
$6C{O}_2$, $18$ ATP, $12NADP{H}_2$

To make one glucose molecule (fix $6C{O}_2$) in $C_4$ pathway requires 30 ATP (18 ATP for $C_3$ pathway + 12 ATP for $C_4$ pathway).