This proposal the basis of the phenomenon whereby the chloroplast ATPase can be activated either by light, or sulfite ions (but in the dark). This unusual effect counteracts (by-passes) inhibition by tightly bound ADP, and allows construction of a chemical model for the effects of membrance high-energy state on the ATPase. The effects of sulfite stimulation of uni-site catalysis in spinach thylakoids vs. effect on steady state rates will be among the objects of this study.
