Chitinase is an enzyme that breaks down chitin, a tough, structural polysaccharide found in the cell walls of fungi and the exoskeletons of arthropods like insects and crustaceans. This enzyme plays a crucial role in various biological processes, including digestion and defense against pathogens. In plants, chitinase helps protect against fungal infections by degrading the chitin in the cell walls of invading fungi. It is also studied for its potential applications in agriculture and biotechnology, where it may be used to enhance crop resistance to pests and diseases.