Hey guys, I can't seem to wrap my head around this question. I thought that 12 ATP were used to create 12 G3P, which split up to yield 10 G3P re-entering the cycle and 2G3P going on to make Glucose. Where do they get "To produce a single 3-carbon G3P molecule a net total of 9 ATP, 3 CO2, and 6 NADPH must be consumed?" Thanks! How many molecules of ATP are needed during the Calvin Benson Cycle to produce a disaccharide such as sucrose? A. 9 ATP. B. 18 ATP. C. 27 ATP. D. [Correct] 36 ATP. E. 45 ATP. Explanation 36 molecules of ATP are needed to produce a single disaccharide, such as sucrose, during the Carbon Benson Cycle. To produce a single 3-carbon G3P molecule a net total of 9 ATP, 3 CO2, and 6 NADPH must be consumed during the Calvin Benson Cycle. However, since the disaccharide sucrose contains 12 carbon atoms it should not be surprising that four molecules of G3P are needed for its synthesis. Therefore, 4 G3P/sucrose X 9 ATP/G3P = 36 ATP/sucrose.