Explain the characteristics of enzymes and the lock and key theory of enzyme action. Explain the role of enzymes in catabolic and anabolic reactions.

1) enzymes are biological catalysts that will speed up reactions by reducing activation energy for the reaction. 2) Lock and key theory concerns how the enzyme (lock) only forms a reactive complex with a specific molecular substrate (key). 3) enzymes are involved in catabolic (breaking molecules down) reactions, such as peptide hydrolysis to amino acids by protease enzymes, and anabolic (building up) reactions, such as the construction of polypeptides from individual amino acids.