Nucleotide metabolism: allopurinol: practice question

The best answer is C, Xanthine oxidase. Allopurinol and febuxostat reduce conversion of hypoxanthine and xanthine to uric acid by inhibiting xanthine oxidase.

PRPP synthetase is involved in nucleotide synthesis.

Adenosine deaminase participates in purine degradation but is not allopurinol's target.

CPS I is the mitochondrial urea-cycle enzyme.

It tests Nucleotide metabolism: allopurinol in Biochemistry. This is useful for chronic urate lowering and tumour lysis prophylaxis.

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.