KROK 1 Stomatology 2015 – Question 31 · KROK (Dentistry)
Mother had noticed her 5-year-old child's urine to become dark in colour. Bile pigments in urine were not detected. The diagnosis of alkaptonuria was made. What enzyme is deficient?
- A. Phenylalanine hydroxylase
- B. Homogentisic acid oxidase
- C. Phenylpyruvate decarboxylase
- D. Tyrosinase
- E. Oxyphenylpyruvate oxidase
Hint
Recall which intermediate of tyrosine catabolism accumulates and darkens in urine on standing, and which enzyme normally breaks it down.
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