Evolution of photosynthesis C photosynthesis is the oldest and most common form. C3 is a plant that uses the calvin cycle for the initial steps that incorporate CO2 into organic material. C4 is a plant that prefaces the calvin cycle with reactions that incorporate CO2 into four-carbon compounds. CAM is a plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. C4 and CAM Plants have special adaptations that save water. The biochemical capacity to use water as the source for electrons in photosynthesis evolved in a common ancestor of extant cyanobacteria. The geological record indicates that this transforming event
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