ATP synthase steady-state flux analysis. We analyzed the dependence on the fluxes through ATP synthases at constant concentrations of adenine nucleotides in the different compartments. We analyzed how the flux changes with the driving forces of the cycles (Eq. 26). (A) ATP net flux through ATP synthases for different concentrations of ADP in the matrix and different membrane potentials. A counterclockwise cycle is defined as positive, favoring ATP hydrolysis. For membrane potentials above 160 mV and larger ADP_m concentrations, ATP is synthesized. (B) ATP net flux through ATP synthases for different pH and membrane potentials (for fixed concentrations of adenine nucleotides).