High Quality Content by WIKIPEDIA articles! The `light-dependent reactions`, or light reactions, are the first stage of photosynthesis, the process by which plants capture and store energy from sunlight. In this process, light energy is converted into chemical energy, in the form of the energy-carrying molecules ATP and NADPH. In the light-independent reactions, the formed NADPH and ATP drive the reduction of CO2 to more useful organic compounds, such as glucose. However, although light-independent reactions are, by convention, also called dark reactions, they are not independent of the need of light, for they are driven by ATP and NADPH, products of light.