Photosynthesis the newly formed NADPH and releases three-carbon sugars, which are later combined to form sucrose and starch. The overall equation for the light-independent reactions in green plants is Carbon fixation produces the intermediate three-carbon sugar product, which is then converted into the final carbohydrate products. The simple carbon sugars produced by photosynthesis are then used in the forming of other organic compounds, such as the building material cellulose, the precursors for lipid and amino acid biosynthesis, or as a fuel in cellular respiration. The latter occurs not only in plants but also in animals when the energy from plants is
Light-harvesting complexes of green plants pigment molecules and the energy they absorb is shuttled by resonance energy transfer to a specialized chlorophyll-protein complex known as the reaction center of each photosystem. The reaction center initiates a complex series of chemical reactions that capture energy in the form of chemical bonds. For photosystem II, when either of the two chlorophyll "a" molecules at the reaction center absorb energy, an electron is excited and transferred to an electron acceptor molecule, pheophytin, leaving the chlorophyll "a" in an oxidized state. The oxidised chlorophyll "a" replaces the electrons by photolysis that involves the oxidation of water molecules to oxygen,