The light-dependent reactions take place inside the chloroplasts in stacks of called . Light from the is absorbed by plant pigments such as . The enegy from sunlight is used to split molecules of . The gas is produced and returned to the atmosphere. The remaining H⁺ ions and (e^-'s) are used to recharge the carrying molecules needed for the light-independent reactions:

The light-independent phase is sometimes called the "" phase because it does not rely directly upon sunlight. The light independent reactions take place in the fluid of the chloroplast called the . The energy carrying molecules ATP and NADPH, which were recharged in the light dependent reactions, are used to incorporate the gas into molecules that make the sugar called . This sugar has the
formula ₆₁₂₆. This set of reactions, powered by ATP and NADPH, is collectively called the cycle.