Question

The number of NADH molecules that are used during the conversion of carbon dioxide into one molecule of glucose are

• A. 1
• B. 4
• C. 6
• D. 8
• E. 12

Answer 1

Answer: (E)

12

Formation of one molecule of glucose (6C) requires 6 turns of Calvin cycle as 3 turns of carbon fixation obtains net one molecule of glyceraldehyde 3 phosphate (G3P; 3C) and two molecules of G3P are required to make one molecule of 6 carbon glucose. One turn of Calvin cycle fixes one molecule of carbon dioxide and requires 2 molecules of NADPH for reduction of 1,3 bisphosphoglycerate into glyceraldehyde 3 phosphate. So, 6 turns of Calvin cycle require 6 x 2= 12 NADPH. Thus, the correct answer is option E.