A photosynthetic reaction center is a complex of three proteins that is the site where molecular excitations originating from sunlight are transformed into a series of electron-transfer reactions. The reaction center proteins bind functional co-factors, chromophores or pigments such as chlorophyll and pheophytin molecules. These absorb light, promoting an electron to a higher energy level within a pigment. The free energy created is used to reduce a chain of electron acceptors which have subsequently lowered redox-potentials, and is critical for the production of chemical energy during photosynthesis.
Reaction centers are present in all green plants and in many bacteria and algae. Green plants have two reaction centers known as photosystem I and photosystem II and the structures of these centres are complex, involving a multisubunit protein. The reaction centre found in Rhodopseudomonas bacteria is currently better understood since it has fewer proteins than the examples in green plants.
Reaction centers are present in all green plants and in many bacteria and algae. Green plants have two reaction centers known as photosystem I and photosystem II and the structures of these centres are complex, involving a multisubunit protein. The reaction centre found in Rhodopseudomonas bacteria is currently better understood since it has fewer proteins than the examples in green plants.
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