Diffusion Barriers for Protons at the External Surface of Thylakoids

Abstract

Light induced electron transfer across photosynthetic membranes of higher plants is coupled with proton translocation from the outer phase into the lumen of thylakoids. The primary photochemical charge separation in PSII transfers one electron to special plastoquinone molecules Q and R which act in series (H.H. Stiehl, H.T. Witt, 1968, 1969; B.A. Diner,1977; B.R. Velthuys, J. Amesz, 1974; B. Bouges-Bocquet, 1973). R stores two electrons and mediates electron transfer into the plastoquinone pool (B.R. Velthuys, J. Amesz, 1974)