Fig. 1
From: A synthetic metabolic network for physicochemical homeostasis
Layout and thermodynamics of the system. a Schematic representation of the arginine breakdown pathway. b Structures of arginine, citrulline and ornithine at neutral pH. c Thermodynamics of arginine conversion for the reactions of ArcA, ArcB, and ArcC1. G0 values were calculated for pH 7.0 and an ionic strength of 0.1 M using eQuilibrator 2.2. d Thermodynamics of the arginine/ornithine antiport reaction. G values were calculated at varying concentration gradients of arginine (outside to inside) and ornithine (inside to outside). When the arginine and ornithine gradients are opposite, that is, [Arg]in < [Arg]out and [Orn]in > [Orn]out, then a negative (and thus favorable) G value is obtained. Four scenarios for the product of the arginine and ornithine gradients are indicated
