title: The origin and evolution of oxygenic photosynthesis.
abstract: The evolutionary developments that led to the ability of photosynthetic organisms to oxidize water to molecular oxygen are discussed. Two major changes from a more primitive non-oxygen-evolving reaction center are required: a charge-accumulating system and a reaction center pigment with a greater oxidizing potential. Intermediate stages are proposed in which hydrogen peroxide was oxidized by the reaction center, and an intermediate pigment, similar to chlorophyll d, was present.
authors.affiliation: Department of Chemistry and Biochemistry, Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe 85287-1604, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Blankenship
authors.forename: H
authors.initials: H
authors.lastname: Hartman
mesh_terms: D001429:Bacteriochlorophylls / Q000378:metabolism; D005075:Biological Evolution; D002734:Chlorophyll / Q000378:metabolism; D000458:Cyanobacteria / Q000502:physiology; D006861:Hydrogen Peroxide / Q000378:metabolism*; D045342:Light-Harvesting Protein Complexes; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000502:physiology*; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins; D014867:Water / Q000378:metabolism
chemical_list: D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D014867:Water; D002734:Chlorophyll; C107509:chlorophyll d; D006861:Hydrogen Peroxide; D010100:Oxygen