Nucleotide metabolism: urinary alkalinisation for uric acid stones: practice question

The best answer is C, Alkalinising the urine with potassium citrate. Uric acid has a pKa of about 5.

Acidifying urine keeps the compound in its insoluble uric acid form.

A high-protein diet increases purine intake and urinary acid load.

Thiazides reduce urate excretion and raise serum urate.

It tests Nucleotide metabolism: urinary alkalinisation for uric acid stones in Biochemistry. 5, so it is poorly soluble in acid urine but far more soluble as urate when urine pH is raised. Potassium citrate raises urinary pH and also reduces calcium stone risk. Acidifying urine and a purine-rich diet increase risk.

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.

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