Kosubstraatit

Kosubstraatit are compounds that are required for an enzyme to catalyze a chemical reaction but are not consumed in the process. They are distinct from substrates, which are the molecules that are directly acted upon by the enzyme and are transformed into products. Kosubstraatit are often involved in facilitating the reaction by providing necessary chemical groups, energy, or by acting as electron carriers.

Many enzymes require kosubstratit for their activity. For example, many oxidoreductase enzymes require coenzymes such as NAD+ or FAD, which act as electron acceptors or donors. Similarly, transferase enzymes often utilize coenzyme A or pyridoxal phosphate to facilitate the transfer of functional groups. Kinases, a type of transferase, require ATP as a kosubstraat to provide the phosphate group.

The distinction between substrates and kosubstratit is important for understanding enzyme kinetics and regulation. While substrates are directly converted to products, kosubstratit are regenerated after the reaction and can be reused. The availability of kosubstratit can therefore limit the rate of an enzyme-catalyzed reaction, and the concentration of kosubstratit can be a factor in cellular metabolism. Some molecules can function as both a substrate and a kosubstraat depending on the specific enzyme and reaction context.