Question

How many NADPH and ATP molecules are used in Calvin cycle for production of trioses required for synthesis of 6 sucrose molecules?

• A. 144 NADPH, 216 ATP
• B. 288 NADPH, 432 ATP
• C. 144 NADPH, 288 ATP
• D. 72 NADPH, 108 ATP

Answer 1

Answer: (A)

144 NADPH, 216 ATP

The net reaction of Calvin cycle or C${}_3$ cycle for 1 surose molecules is :

$6RUBP+6C{O}_2+18ATP+12NADPH\to 6RUBP+C_6{H}_{1}2O_6+18ADP+12{NADP}^{+}+18Pi$.

For the production of 1 sucrose molecules- 12 NADPH and 18 ATP required, In one sucrose molecules 2 trioses (3-phosphoglyceraldehyde and dihydroxyacetone phosphate) are there. So, 24 NADPH and 36 ATP are there.

For the production of trioses required for synthesis of 6 sucrose molecules is 144 NADPH and 216 ATP are used.

Hence, the correct answer is '144 NADPH, 216 ATP'.