How do enzyme activities control metabolite concentrations? An additional theorem in the theory of metabolic control.

A simple theorem is derived relating the extent to which enzymes in a metabolic pathway control the steady-state concentration of metabolites to the kinetic properties of those enzymes. The theorem gives insight into the mechanism by which the concentration of a second messenger is controlled by the enzymes that form and degrade it, and provides an alternative to the 'cross-over theorem'.