The Michaelis-Menton Equation has a very similar form to the Hill Equation but the key difference is that it deals with enzyme rates not ligand/receptor or drug/target interactions per se. Basically, it describes how fast an enzyme (E) makes its product (P) as a function of the total concentration of substrate ([*S*]* _{t}*). This rate of production formation (d[P]/dt) is proportional to the

*k*and the amount of complex ([ES]) which is exact what the Michaelis-Menton equation models. The Michaelis-constant (

_{cat}*K*= (

_{m}*k*+

_{off}*k*) /

_{cat}*k*) describes how tightly the substrate binds the enzyme and the

_{on}*k*is a rate-constant that describes how quickly the enzyme can make the product. Here,

_{cat}__denote concentrations and a t subscript indicates “total concentrations.”__

*brackets*