Fig. 3: Efficiency and power for the self-regulating chemical reaction network (CRN) in Fig. 2.
From: Gears in chemical reaction networks for optimizing energy transduction efficiency
a Efficiency η of the CRN as a function of the concentration [S], represented by the ratio ΔATPG/ΔSPG, with ΔATPG = 20, RT, for three values of the parameter q (q = 0.4, 0.45, and 0.47, corresponding to the green, blue, and yellow curves, respectively). q is the value on the x-axis where [E1] = [E2], interpreted as the effective switching point from gear ψ2 to ψ1. The black curve shows, for comparison, the efficiency of the CRN without regulation ([E1] = [E2] for all [S]), while the dashed curve shows the optimal efficiency from Eq. (4). b The output power P divided by Pmax for the previous q values. Pmax, shown in the inset, is the maximal power achievable under the given operating conditions with the constraint [E1], [E2] ≤ L. It is realized by using all the enzymes available before ΔATPG/ΔSPG < 1/2 and only all the E1 after. c Parametric plot of output power versus efficiency as a function of substrate concentration [S]. The different curves correspond to different q values as in the other plots. The markers indicate 12 equally spaced values of ΔATPG/ΔSPG in the range [0.3, 0.9]. The vertical axis represents the efficiency rescaled by α = ΔATPG/ΔSPG.
