Bioprocess Engineering: Basic Concepts, 3rd Edition

3. Enzymes

Enzymes are usually proteins of high molecular weight (15,000 < MW < several million daltons) that act as catalysts. Recently, it has been shown that some RNA molecules are also catalytic, but the vast majority of cellular reactions are mediated by protein catalysts. RNA molecules that have catalytic properties are called ribozymes. Both ribozymes and enzymes are specific, versatile, and very effective biological catalysts, resulting in much higher reaction rates as compared to chemically catalyzed reactions under ambient conditions.

More than 2000 enzymes are known. Enzymes are named by adding the suffix -ase to the end of the substrate, such as urease, or to the end of the reaction catalyzed, such as alcohol dehydrogenase. Some enzymes ...