It is observed that when the concentration of acetylcholine remains constant in the reaction of an aqueous solution, the speed of the enzyme-catalyzed reaction or the formation of the product increases with increasing concentrations of substrate.
The reaction rate is directly proportional to the concentration of acetylcholine.
At very low concentrations of acetylcholine, there is a small increase in the concentration of the substrate which results in a large increase of the rate in reaction.