Peptidases are enzymes that break down proteins into smaller peptides or amino acids. They play a crucial role in digestion by helping to process dietary proteins in the stomach and small intestine. By cleaving peptide bonds, peptidases ensure that the body can absorb the necessary nutrients from the food we eat. There are different types of peptidases, including serine peptidases, cysteine peptidases, and metallopeptidases, each classified based on their active site composition. These enzymes are also involved in various biological processes, such as cell signaling and immune responses, highlighting their importance beyond digestion.