Enzyme Concentration

Provided substrate is available in excess (i.e., is not the limiting factor), the rate of an enzyme-catalysed reaction is directly proportional to the concentration of enzyme present. This is because each additional enzyme molecule provides one more active site capable of independently binding and processing substrate at the same time, so doubling the amount of enzyme roughly doubles the number of reactions that can occur simultaneously, and therefore roughly doubles the overall reaction rate. This straightforward relationship is why processes such as enzyme-based diagno …