Components of Calvin Cycle Requirements or Functions A. CO2 1. Molecule that enters the Calvin cycle and requires energy for fixation. B. ATP 2. Required in the Calvin cycle; 3 molecules are needed per CO2 molecule fixed. C. NADPH 3. A process that produces additional ATP to balance the ATP and NADPH requirements. D. Cyclic Phosphorylation 4. Required in the Calvin cycle; 2 molecules are needed per CO2 molecule fixed

Step-by-step solution

A - 1: CO2 is the molecule that enters the Calvin cycle and requires energy (ATP and NADPH) for fixation. B - 2: ATP is required in the Calvin cycle, with 3 molecules needed for every CO2 molecule fixed. C - 4: NADPH is also required in the Calvin cycle, with 2 molecules needed per CO2 molecule fixed. D - 3: Cyclic phosphorylation produces additional ATP to balance the difference in the number of ATP and NADPH required in the Calvin cycle.