The Michaelis constant, often denoted as Km, is a key parameter in enzyme kinetics that helps describe how efficiently an enzyme converts a substrate into a product. It represents the substrate concentration at which the reaction rate is half of its maximum velocity (Vmax). A low Km value indicates high affinity between the enzyme and substrate, meaning the enzyme can effectively bind to the substrate even at low concentrations. Understanding the Michaelis constant is crucial for studying enzyme behavior in biological systems. It allows researchers to compare different enzymes and their efficiencies, providing insights into metabolic pathways and potential drug targets.