What is the limiting factor, export through ANTs or production of ATP through ATP synthases? We changed the ratio of ANTs to ATP synthases to answer this question and used the ODE model to estimate the impact on ATP production, for a constant concentration of ADP in the IMS and a constant membrane potential of 180 mV. (A–C) Number of molecules measured over time in the different compartments. (D) Number of ATP molecules measured over time in the cytosol relative to the initial number. (E) Number of ATP molecules in the cytosol after 1 s relative to the initial number of molecules, for different ratios of ANTs/ATP synthases. Ratios go from 1 to 24, the number of ATP synthases is kept constant, and the number of ANTs increases (fast ANTs were considered r = 10).