Peroxidase is an enzyme that catalyzes the breakdown of peroxides, particularly hydrogen peroxide, into water and other harmless substances. This process is essential for protecting cells from oxidative damage caused by reactive oxygen species. Peroxidases are found in various organisms, including plants, animals, and microorganisms, and play a crucial role in various biological processes. In plants, peroxidases are involved in processes such as lignin synthesis and response to stress. In humans, they contribute to the immune response by helping to eliminate pathogens. Overall, peroxidases are vital for maintaining cellular health and supporting various metabolic functions.