Question

Twelve more ATP molecules are required for glucose formation in $C_4$ palnts because 2 additional ATP molecules are utilized per turn in

• A. Carboxylation of PEP
• B. Regeneration of RuBP
• C. Regeneration of PEP
• D. Reduction reaction

Answer 1

The correct option is C

Regeneration of PEP

The regeneration of PEP from pyruvic acid after it is transported back into mesophyll cells requires 2 ATP molecules per molecule of $C{O}_2$ fixed. Hence 12 additional ATP molecules are required for the production of one molecule of glucose in $C_4$ plants. Rest all the steps consume the same amount of energy as in $C_3$ plants.