The reaction center accepts excitation energy, but it doesn't pass the energy on to another pigment. Electron transport systems are studied in chapter 6. Electron flow may be cyclic or noncyclic. ATP can form when electrons cycle from and back to a type I photosystem. The noncyclic pathway of photosynthesis.
Orange arrows symbolize electron flow.
Now, both cyclic and noncyclic pathways of electron flow operate in all photosynthetic organisms. They occur as a cyclic pathway called the Calvin-Benson cycle. After this, glucose is primed to enter other reactions Since environments differ, so do the exact details of photosynthesis. We will briefly give examples of the different ways of fixing carbon in weather which is hot and dry. Here is a summary of the chapter.