The model uses the Nernst-Planck equation to describe the potential distribution within the electrode, alongside the kinetics of the enzyme which is assumed to be homogenously distributed within the porous electrode. Furthermore, known modifiers on enzyme activity such as pH and substrate concentration that are described using common analytical expressions such as Michaelis-Menten kinetics are included where appropriate. Finally, this is combined with a mass transport model that incorporates the kinetics and thermodynamics of solution reactions. This approach gives a model that is predictive of electrode currents and performance and, critically, is completely independent of the experimental data. This prediction of experimental currents across a range of conditions and the excellent agreement of the predicted and experimental values provides validation of the model. Furthermore, it is indicative of the absence of additional unconsidered interactions, demonstrating that a more comprehensive analysis than that presented was not required.