Answer to Question #102810 in Chemistry for laparjhandus

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

Task:

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

Solution:

The reactions include:

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

C₅H₈P₂O₁₁^4- + CO₂ + H₂O → 2 C₃H₄PO₇^3- + 2 H⁺_(aq)

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

6 C₃H₄PO₇^2- + 6 ATP = 6 C₃H₄P₂O₁₀^4- + 6 ADP

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

6 C₃H₄P₂O₁₀^4- + 6 NADPH + H⁺_(aq) = 6 C₃H₅PO₆^2- + 6 NADP⁺ + 6 P_i

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

5 C₃H₅PO₆^2- + 2 H₂O → 3 C₅H₉PO₈^2- + 2 P_i

2 glyceraldehyde-3-phoshate = 2 dihydroxyacetone phoshate

2 C₃H₅PO₆^2-  = 2 C₃H₅PO₆^2-

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

C₃H₅PO₆^2- + C₃H₅PO₆^2-  = C₆H₁₀P₂O₁₂^4-

The Calvin Cycle equation is: 3CO₂ + 6NADPH + 5H₂O + 9 ATP → G3P + 2 H⁺ + 6 NADP⁺ + 9 ADP + 8 P_i

So according to that, to make 1 molecule of glucose, you need 6 moles of CO₂:

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

Answer: 18 moles of ATP and 12 moles of NADPH.