how many atp molecules are needed to regenerate rubp
Regeneration Phase of the Calvin Cycle Overview. We've consumed three molecules each of RuBP, CO 2 and H 2 O, plus six ATP and six NADPH molecules. We now have six Glyceraldehyde 3-phosphate (GAP) molecules. Five of these are needed to regenerate the original three RuBP molecules, which completes one turn of the Calvin Cycle. The sixth GAP molecule is extra. It was built using the three carbon atoms brought into the cycle by the three CO 2 molecules in Step two.