In almost all land animals, urate oxidase further catalyzes the oxidation of uric acid to allantoin, but in humans and most higher primates, the urate oxidase gene is nonfunctional, so that UA is not further broken down.
Urate oxidase further catalyzes the oxidation of uric acid to allantoin. This is in almost all land animals. The urate oxidase gene is nonfunctional. This is in almost all land animals. This is in humans. This is in most higher primates. UA is not further broken down.