1. ATP: ATP produced by cyclic and acyclic photophosphorylation provides the energy required for the Calvin cycle.
2. NADPH+H+ : The acyclic photophosphorylation process produces NADPH+H+ which acts as a catalyst in the cycle.
3. CO2 : Atmospheric CO2 plays a special role in the production of sugars in this cycle.
4. RuBP: RuBP combines with CO2 to initiate the Calvin cycle.