The Michaelis-Menten model is based on the formation of an enzyme-substrate complex and its subsequent conversion into a product. The rate of this reaction is determined by the concentration of the substrate and the intrinsic properties of the enzyme. It is expressed by the equation: v = (Vmax [S]) / (Km + [S]) where v is the rate of reaction, Vmax is the maximum rate of reaction, Km is the Michaelis constant, and [S] is the substrate concentration.