Free energy transduction in chemical reaction networks from enzymes to metabolism*

I will rigorously define energy transduction in open chemical reaction networks (CRNs). The method is based on the stoichiometric matrix and the chemostatted species to identify the fundamental set of thermodynamic forces and fluxes contributing to the CRN dissipation at steady state. Transduction arises when some fluxes flow against their force thus creating negative contributions to the dissipation. This is possible because other fluxes power transduction by being aligned with their force and ensuring the overall positivity of the dissipation. Transduction is an emergent phenomenon arising at the network level because fluxes of elementary reactions are always aligned with their force. I will apply our method to study the efficiency of metabolic pathways in central metabolism. Our method generalizes to arbitrary (nonlinear) CRNs the work by Terrell L. Hill on free energy transduction in pseudo first order (linear) CRNs.