Figure 2.

Model quantification of the proton motive force (PMF)

(A) Coupling of reactions transporting charges or protons across the inner mitochondrial membrane to the PMF as exemplified by the ADP/ATP translocase, resulting in net transfer of a negative charge, and electroneutral but proton coupled phosphate carrier.

(B) Coupling of the respiratory chain complexes and ATP synthase to the proton motive force. The components transfer PMF corresponding to the number of protons translocated across the inner membrane.

(C) Effect of explicitly modeling the PMF on the operational phosphate/oxygen ratio (P/O) and the simulated growth-associated maintenance cost (GAEC).

(D) Overall fraction of the generated PMF used for transport across the inner membrane, and synthesis of ATP.

(E) P/O ratio and biomass yield at increasing growth rate. Ethanol indicates that simulations were carried out with ethanol as a carbon source.