| PubChem=389 | SMILES=C(CC(C(=O)O)N)CN | MeSHName=Ornithine }} |Section2= |Section3= }} Ornithine's an amino acid which plays a role in the urea cycle. Role in urea cycle L-Ornithine's one of the products of the action of the enzyme arginase on L-arginine, creating urea. Therefore, ornithine's a central part of the urea cycle, which allows for the disposal of excess nitrogen. Ornithine's recycled and in a manner's a catalyst. First, ammonia's converted into carbamoyl phosphate (phosphate-CONH2… (More on Ornithine)