Photosynthesis is a redox process. In this process, in the presence of light, water is oxidized to produce O2, and in the absence of light, CO2 is oxidized to form sugars. In 1905, Blackman divided the photosynthesis process into two stages. Light phase and light neutral phase.
Light Phase
The phase of photosynthesis that takes place in the presence of light is called the photophase. In 1957, Arnon and his colleagues described two types of photophosphorylation in the light phase. Cyclic photophosphorylation and acyclic photophosphorylation. Both processes can run simultaneously if necessary.