Bacterial Photosynthesis

Abstract

There is a photooxidation and transfer of electrons from cytochrome to a low potential compound (probably ferredoxin) in photosynthetic bacteria. The subsequent back-flow of electrons between ferredoxin and cytochrome through the redox reagents built into the photosynthetic apparatus results in the cyclic phosophosphorylation. Other facets of the cell''s physiology determined how this basic photosynthetically driven electron transport scheme cooperates and functions in conjunction with the regular dark enzymatic respiratory mechanisms. The general CO2 fixation scheme (acting through reduced-diphosphopyridine-nucleotide) is similar in all cases. Great variety occurs in the substrate which is oxidized concurrently with CO2 reduction. Organic molecules may be directly assimilated into the photosynthesizing cell. There may be a great many variations in this basic theme of bacterial photosynthesis. The photosynthetic process consists of the cyclic electron transfer mechanism for a representative bacterium. The photooxidation of the accessory H donor and photoreduction of CO2 as needed in the economy of the cell are associated with this cyclic system.