 The photosynthesis is actually divided into two parts. There's the light part and the dark part. The light part is all about capturing sunlight and turning it into storable forms of energy that the plant can then use for other things. So it creates ATP and it also creates a compound called NADPH which it uses later on as a proton source. Those things drive the second part of photosynthesis which are the dark processes which are the ones that most of us learn about in painful chemical cycles like the Calvin-Basham-Benson cycle, also known as the C3 cycle. It's called the C3 cycle because the first things that it produces are three carbon compounds. But the whole process is driven by the ATP and the NADPH that was created in the light part of photosynthesis. So they also require, if you look at the Calvin cycle, you'll see there are a number of phosphorylated compounds actually occur within the cycle. For example, during the synthesis of glucose, it passes through fructose 6-phosphate to glucose 6-phosphate and then finally to glucose. So it's a vital part of the chemistry as well as of the energy processes that drive the cycle around.