This document discusses enzymes and their role in biochemistry. It begins with an introduction to enzymes, noting that they are proteins that act as biological catalysts. It then covers the characteristics, classification, functions, examples, properties, structure, and role of enzymes in metabolism. Enzymes are classified based on the reactions they catalyze. They play important roles in biological processes and have many industrial applications, such as in food processing, brewing, and biofuel production. The structure of enzymes allows them to bind specifically to substrates and catalyze reactions without being used up in the process. Enzymes are essential catalysts that allow metabolic reactions to occur efficiently in living organisms.