[Relationships of photoreduction of substituted salts of 4,4'-dipyridyl by isolated chloroplasts].

Kinetic relationships of photoreduction of 4,4'-dimethyldipyridyl and 4,4'-dibenzyldipyridyl in the presence of chlorplast were studied. It was found that photoreduction leads to the establishment of photosteady state in which the rate of photoreduction is equal to the rate of dark oxidation of reduced form. Kinetics of dark oxidation of photoreduced form were investigated. The study of inhibition of photoreduction of methylviologen and potassium ferricyanide by diuron was performed. It was shown that the nature of inhibition of both reactions is completely identical. The effect of hydrogen ions concentration and gas phase composition was studied. Stabilization of low potential electron acceptors to the oxidation by molecular oxygen in the reaction of photooxidation of water is discussed.