Question

In $c_4$ plants, number of ATP and $NADP{H}_2$ molecules required to fix 2 molecules of $C{O}_2$ are respectively.

• A. 6 & 10
• B. 10 & 6
• C. 4 & 10
• D. 10 & 4

Answer 1

The correct option is D 10 & 4

Under ideal conditions, five ATP and two NADPH are required for every CO${}_2$ fixed in C4 photosynthesis (two ATP are required to run the CO${}_2$ pump, i.e., regenerate PEP). Hence, for two CO${}_2$, 10 ATP and 4 NADPH are required.

So, the correct option is '10 & 4'.