The energy for the photosynthesis reaction is gained in the first stage of the reaction.
There are 2 stages in photosynthesis:
- The light-dependent stage
- The light-independent stage
During the light-dependent stage, an electron in the molecules of chlorophyll gets excited and gets knocked off as a result of photon absorption. A molecule of water is split and the electrons released replace the one lost by the chlorophyll after traveling through the electron transport chain.
The energy from the traveling electron is used to reduce NADP+ to NADPH while the splitting of water to H and O means that a proton gradient is established between the stroma and the thylakoid lumen of the chloroplast. The electrochemical gradient thus created is used by ATP synthase to generate ATP from ADP.
The two chemicals, ATP and NADPH, are then utilized as energy sources for the light-independent reaction.
More on photosynthesis can be found here: https://brainly.com/question/1388366
