substraattikoncentraatio

Substraattikoncentraatio, or substrate concentration in English, refers to the amount of a specific reactant, known as the substrate, present in a solution or system where a chemical reaction is occurring. This concentration is a critical factor in determining the rate of many biochemical and chemical processes, particularly enzyme-catalyzed reactions.

In enzyme kinetics, the Michaelis-Menten model famously describes the relationship between reaction velocity and substrate concentration. At low substrate concentrations, the reaction rate is directly proportional to the substrate concentration, meaning that as more substrate is added, the reaction proceeds faster. However, as the substrate concentration increases further, the enzyme active sites become saturated with substrate molecules. At this point, the enzyme is working at its maximum velocity (Vmax), and further increases in substrate concentration have little to no effect on the reaction rate. The substrate concentration at which the reaction velocity is half of Vmax is known as the Michaelis constant (Km).

Understanding substrate concentration is vital in various fields, including medicine, where it can influence drug efficacy and metabolism, and industrial biotechnology, where it is optimized for efficient production of desired compounds. Changes in substrate concentration can also be indicative of cellular metabolic states or environmental conditions. The measurement and manipulation of substrate concentrations are therefore fundamental techniques in experimental and applied science.