Proton translocation induced by ATPase activity in chloroplasts.

Proton uptake by chloroplasts was induced by light-triggered ATPase activity. A quotient of two was obtained when the initial rate of proton uptake was divided by the rate of P(i) released from ATP. Gramicidin accelerated the rate of ATPase activity and reduced the H(+)/P(i) ratio to 1.4. The results were found to be consistent with the chemiosmotic theory.