title: [Role of ferredoxin in pseudo-cyclic electron transport in isolated pea chloroplasts].
abstract: The pseudo-cyclic electron transport in isolated pea chloroplasts in a medium without exogenous cofactors but containing methylviologen and ferredoxin was studied. In order to establish the steps limiting the electron transport, the rates of electron transport a different pH values and under phosphorylating and non-phosphorylating conditions in the presence of the uncoupler--gramicidin D--were determined. It was shown that in the absence of exogenous cofactors the total electron transport is limited by a stage of electron transfer from the acceptor site of photosystem I to oxygen. An addition of ferredoxin or methylviologen stimulates oxygen consumption. It was shown that the plot of the dependence of the rate of oxygen consumption on ferredoxin concentration is two-phase in contrast to that of methylviologen concentration, which is indicative of the existence of two competitive reactions of oxygen reduction involving ferredoxin (with different Km values for the protein).
mesh_terms: D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D004579:Electron Transport; D005288:Ferredoxins / Q000378:metabolism*; D006096:Gramicidin / Q000494:pharmacology; D007700:Kinetics; D010101:Oxygen Consumption / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D010944:Plants / Q000378:metabolism
chemical_list: D005288:Ferredoxins; D006096:Gramicidin
vernacular_title: Uchastie ferredoksina v psevdotsiklicheskom elektronnom transporte v izolirovannykh khloroplastakh gorokha.