Past exam of the mathematics and the environment and mathematical physiology course of the University of Oxford / 2009 / B / 4 / d / iii / Solution

The exterior free-substrate equation gives $B_e=J$ at steady state. Thus $k_{+}{s}_e{c}_e-k_{-}{p}_e=J$, andThe sign of the current term is opposite to the interior relation because substrate is supplied to the exterior and removed from the interior. Nonnegative occupancies are selected by the complete steady transport solution and compatible substrate totals.