A network in which all species are coupled to a chemostated spontaneous process. This system can be extended to a cyclic reaction network by considering the outcome if both RCO2Me and R`CO2Me are in direct exchange with RCO2 - (Figure ). Simple analysis (see ESI) allows us to generate expressions for the relative concentrations of the species involved (see ESI) and the ratchetting constant, r0 (Figure , equation 2), whose value quantifies flux in the network; 13f if r0 is equal to 1 there is no net flux, whereas if it deviates from 1, detailed balance is broken and there is net flux around the cycle RCO2Me→RCO2 -→R`CO2Me at non-equilibrium steady state.