Serine proteases are a group of enzymes that play a crucial role in various biological processes by breaking down proteins. They are named for the serine amino acid in their active site, which is essential for their enzymatic activity. These enzymes are involved in digestion, immune response, and cell signaling, making them vital for maintaining health. These proteases function by cleaving peptide bonds in proteins, which helps regulate many physiological functions. Examples of serine proteases include trypsin, chymotrypsin, and thrombin. Their activity is tightly regulated, as uncontrolled protease activity can lead to diseases such as cancer and inflammation.