STEP ONE: Harvesting Radiant Energy The first step of photosynthesis occurs in the chloroplasts of plant cells. Light photons are absorbed by a pigment called chlorophyll, which is abundant in the thylakoid membrane of each chloroplast. Chlorophyll appears green to the eye because it does not absorb green waves on the light spectrum. It reflects them instead, so that’s the color you see. STAGE 2: Converting Radiant Energy After radiant energy from sunlight is absorbed, the plant converts light energy into a usable form of chemical energy to fuel the plant’s cells STAGE 3: Storing Radiant Energy The last stage of the photosynthesis process is known as the Calvin-Benson cycle, in which the plant uses atmospheric carbon dioxide and water from soil to convert ATP and NADPH. The chemical reactions that make up the Calvin-Benson cycle occur in the stroma of the chloroplast.
