Type b Cytochrome - There is evidence that a b-type cytochrome IS present in the photosynthetic electron transport system.
Cytochrome b has been demonstrated in Rhodopseudomons sphaeroides (E°‘ = + 50, mV) and R. capsulata (E°' = + 60 mV), and there are indications that it is adjacent to cytochrome c in the cyclic system. It is likely that cytochrome b may be present even in organisms where it has been previously reported to be absent.





