[Kinetic model of the operation of a 2-electron switch in the photosynthetic reaction center of bacteria].

A mathematical model, describing the binary oscillation of the concentration of semiquinone form of the secondary acceptor (ubiquinone) in photosynthetic reaction center of purple bacteria is proposed. This model takes into account both the changes of the ubiquinone state when the chromatophores are subjected to short flashes of light, and the successive dark relaxation of the semiquinone form. The model allows to calculate such characteristics as the dependence of the flash number, the stationary level of semiquinone form which is being established, when the flash number increases, the velocity which the concentration of semiquinone form is aspirating towards this stationary level and other characteristics. The model shows that the quantum yield of primary charge separation on the reaction center is higher after odd-number flashes then after even-number flashes.