Why it"s important: the vast majority of earth"s energy enters the biosphere through a process called photosynthesis. In the process of photosynthesis chlorophyll and other related pigments capture photons of light energy, this captured energy is used to convert carbon dioxide into complex energy rich molecules. The two parts of photosynthesis: 2 distinct stages of photosynthesis: light-dependent reactions, and light- independent reactions. Pigment molecules capture light energy, and then use this energy to synthesize nadph and atp. This is executed via the electron transport chain, which uses electrons donated from water. The splitting of water produces a byproduct of oxygen, which is then released into the environment. Formula for light- dependent: 2h2o + light energy 4h+ + 4e- + o2. Co2 fixation occurs during this stage, co2 is converted from the inorganic to organic form using the electrons carried by nadph and the energy from atp.