Question

How many ATP and NADPH + H+ are required for the synthesis of 1 molecule of glucose in c3 and c4 plants respectively ?

• A. 30ATP ,12NADPH and 18ATP, 12NADPH
• B. 18ATP, 12NADPH and 30ATP ,12NADPH
• C. 30ATP ,12NADPH and 16ATP, 12NADPH
• D. 32ATP ,12NADPH and 18ATP, 12NADPH

Answer 1

Answer: (B)

18ATP, 12NADPH and 30ATP ,12NADPH

In C${}_3$ pathway in Calvin cycle, one CO${}_2$ molecule require 3ATP and 2 NADPH and as the cycle turn to be six times for the formation of one glucose molecule 18 ATP and 12 NADPH are required while in C${}_4$ plant one CO${}_2$ molecule needs 5 ATP molecule as the process occurs in mesophyll cells to bundle sheath cells and came back to mesophyll cells again requires more energy so in six turns of cycle 30 ATP and 12 NADPH are required.

So the correct option is 18 ATP, 12 NADPH, and 30 ATP and 12 NADPH".