In order to characterize the exact dynamic behavior of a spatially delimited catalytic network it is necessary to discern the kinetic parameters governing every participating molecule type. Such detailed knowledge allows the exploration of complex systems and their emergent properties in rigorous computer simulations. An example of this approach is the analysis of the dynamics of complex enzymatic reaction systems in live cells by Monte Carlo simulations , which requires knowledge of the relevant Michaelis-Menten kinetic constants. The dynamics is inferred from the time-dependence of concentrations of network components. The GARD model addresses the needed parameters for such analyses, while other models often do not consider molecular concentrations and/or catalytic constants (Figure ), with some exceptions . Another quantitative factor addressed in the GARD model and missing elsewhere is kinetic constants for the entry and exit of externally supplied molecules (Figure ).