The Michaelis-Menten equation models the kinetics of enzymatic reactions as $$ v = \frac{\mathrm{d[P]}}{\mathrm{d}t} = \frac{V_\mathrm{max}[\mathrm{S}]}{K_m + [\mathrm{S}]}, $$ where $v$ is the rate of the reaction converting the substrate, S, to product P, catalysed by the enzyme. $V_\mathrm{max}$ is the maximum rate (when all the enzyme is bound to S) and the Michaelis constant, $K_m$, is the substrate concentration at which the reaction rate is at half its maximum value.

Plot $v$ against $[\mathrm{S}]$ for a reaction with $K_m = 0.04\;\mathrm{M}$ and $V_\mathrm{max} = 0.1\;\mathrm{M\,s^{-1}}$.