Answer to Question #101803 in Chemistry for Sana

Question

How many moles of ATP and NADPH are required to convert 6 moles of CO2 to fructose-6-phosphate? Give all the reactions involved.

Answer 1

The balanced equation for the net reaction of the Calvin cycle (CO₂ fixation) is:

6CO₂ + 18ATP + 12NADPH + 12 H₂O = C₆H₁₂O₆ + 18 ADP + 18 P_i + 12 NADP⁺ + 6H⁺

The reactions include:

- Ribulose-1,5-bisphosphate + CO₂ = 3-Phosphoglycerate (carboxylation)

- Phosphoglycerate + 2 ATP = 1,3-Bisphosphoglycerate + ADP (reduction, step 1)

- 1,3-Bisphosphoglycerate + 2 NADPH = Glyceraldehyde 3-phosphate + NADP⁺ (reduction, step 2)

- 5 Glyceraldehyde 3-phosphate + 3 ATP = 3 Ribulose-1,5-biphosphate + 3 ADP (regeneration)

- Glyceraldehyde 3-phosphate + dihydroxyacetone phosphate = fructose-6-phosphate (hexose synthesis).

Answer: 18 ATP and 12 NADPH