On the Mechanism of Benzoquinone Penetration and Photoreduction by Whole Cells

Abstract

Short time treatment of intact Porphyridium cruentum cells with benzoquinone results in changes of the cell membranes, which lead to a higher permeability. This increased permeability allows the measurements of photosynthetic electron transport reactions with various electron donors, ac. ceptors and mediators, which cannot enter untreated cells. The capacity of benzoquinone to act as a Hill - reagent in vivo is interpreted as due to a double action of this compound: changing the permeability of the cells by reacting with the cell membrane coupled with the ability of the unreacted molecules to serve as electron acceptors.