Xanthine oxidase catalyzes the conversion of purines into which compound?

• A. Uric Acid
• B. Xanthine
• C. Hypoxanthine
• D. Guanine

Answer: (A)

Xanthine oxidase drives the breakdown of purines down to the final oxidation product uric acid. It performs two sequential oxidation steps: hypoxanthine to xanthine, and then xanthine to uric acid. Thus, the compound produced at the end of this enzymatic sequence is uric acid, making that option the correct choice. Xanthine and hypoxanthine are earlier intermediates, not the final product, and guanine is not produced in this pathway.