Phototrophy is the process by which organisms trap photons and store energy as chemical energy in the form of adenosine triphosphate (ATP). ATP transports chemical energy within cells for metabolism. There are three major types of phototrophy: Oxygenic and Anoxygenic photosynthesis, and Rhodopsin-based phototrophy. Photosynthesis is a chemical process that converts carbon dioxide into different organic compounds using solar energy. Oxygenic and anoxygenic photosynthesis undergo different reactions in the presence and absence of light (called light and dark reactions, respectively). In anoxygenic photosynthesis, light energy is captured and stored as ATP, without the production of oxygen. This means water is not used as primary electron donor
