Flash-Induced ATP Synthesis in Pea Chloroplasts

Abstract

The onset of the ATP synthesis in chloroplasts depends on the activation of the ATPase (Mills, J.D. et al., 1980) and on the energy balance (Graber, P., Schlodder, E., (1980). Girault, G., Galmiche, J.M. (1978) have prepared, from preilluminated leaves, chloroplasts which hydrolyze ATP in the dark and keep this property quite a long time. We propose to follow the synthesis of ATP induced by single turnover flashes in such chloroplasts with a fully active ATPase system as a function of the number of flashes already fired. In those chloroplasts the synthesis of ATP, induced by single turn-over flashes, is controlled by the pH difference across the thylakoid membrane and by kinetic factors which do not seen, to be directly related either to the proton motive force across the membrane or to the hydrolytic activity of the ATPase system.