Photosynthetic Units of Phototrophic Organisms

Photoautotrophic organisms play a key role in the biosphere of the Earth, converting solar energy of the 350-1000 nm range into biochemically available form. In contemporary aquatic and terrestrial ecosystems, the dominating groups are the oxygen evolving cyanobacteria, algae, and higher plants. Anoxygenic phototrophic microorganisms occupy mainly ecological niches with extreme environmental conditions. Despite diverse evolution of all these taxonomic groups, their photosynthetic apparatus has a similar molecular design and identical principles of operation. This review covers recent data about features of the structural and functional organization of pigment-protein complexes of the basic types of photosynthetic units in prokaryotes and eukaryotes. A correspondence between the optical properties of various photosynthetic units and the natural light conditions is discussed.