Coupling to the proton gradient

Photosynthetic systems have provided many avenues for exploration of the proton gradient and its coupling to other membrane phenomena. Some of these reflect unique aspects of the photosynthetic apparatus, - for example the "membrane voltmeters" associated with electrochromic color changes of photosynthetic pigments, and the phenomenon of delayed fluorescence, and its coupling to the proton gradient. Others, - for example the measurement of rapid protolytic reactions, - are much easier in photosynthetic systems because of the easy of activation by flash-llumination. In this lecture, we explore several of these secondary effects of the proton gradient.