Arginase I is an enzyme that plays a crucial role in the urea cycle, which is responsible for removing excess nitrogen from the body. It catalyzes the conversion of arginine, an amino acid, into ornithine and urea. This process helps regulate nitrogen levels and is essential for maintaining metabolic balance. Arginase I is primarily found in the liver, where it contributes to detoxifying ammonia produced during protein metabolism. Abnormal levels of this enzyme can be associated with various health conditions, including liver disease and certain cancers, highlighting its importance in human health and disease management.