To synthesise one molecule of glucose, a maize plant requires more energy than a tomato plant. How many additional ATP molecules are consumed by the maize plant for this process, and in which specific cells is this extra ATP utilised?

Step-by-step solution

Maize is a C ₄ plant, while tomato is a C ₃ plant. In C ₃ plants, the synthesis of one glucose molecule requires 18 ATP and 12 NADPH . In C ₄ plants, the synthesis of one glucose molecule requires 30 ATP and 12 NADPH . The additional 12 ATP ( 2 ATP per CO ₂ molecule fixed) are required to regenerate phosphoenolpyruvate (PEP) from pyruvate. According to the C ₄ pathway (Hatch and Slack pathway), the regeneration of PEP takes place exclusively in the mesophyll cells. Answer: 12 ATP , Mesophyll cells