* ATP (Adenosine Triphosphate): This molecule is the primary energy currency of cells. ATP is generated during the light reactions by harnessing the energy from sunlight. The dark reactions use this energy to drive the process of carbon fixation.
* NADPH (Nicotinamide Adenine Dinucleotide Phosphate): This molecule is a reducing agent, carrying high-energy electrons. It is also generated during the light reactions. NADPH is used in the dark reactions to reduce carbon dioxide and convert it into sugar.
These two molecules, ATP and NADPH, are the "products" of the light reactions that are directly utilized by the dark reactions, also known as the Calvin Cycle.
