This document discusses proteases, which are enzymes that break down proteins. It notes that proteases are widely distributed in biological systems and constitute over 70% of industrial enzymes. Proteases have a wide range of applications including in detergents, food processing, pharmaceuticals, and leather tanning. The document categorizes proteases based on their source (animal, plant, bacterial, fungal), proteolytic mechanism (serine, threonine, cysteine, aspartic, metallo), and pH range (acidic, neutral, alkaline). It provides examples of major industrial uses of proteases in bread making, cheese production, and soy sauce manufacturing. Protease applications also include meat tenderizing, medicine