“…The action of uncouplers alone or in the presence of other ionophores further emphasizes this point because they are without effect on the light-induced protonation changes in isolated purple membrane, at least in the concentrations used here . The action of these ionophores also strongly suggests that the light-driven proton translocation is an electrogenic process; a conclusion for which more direct evidence has already been published on similar model systems (Drachev, Jasaitis, Kaulen, Kondrashin, Liberman, Nemecek, Ostroumov, Semenov & Skulachev, 1974;Kayushin & Skulachev, 1974;Racker & Hinkle, 1974;Yaguzhinsky, Boguslavsky, Volkov & Rakhmaninova, 1976). The organization of bacteriorhodopsin in the vesicle wall is obviously a dominating factor determining the direction and extent of the light response.…”