If urine sample darkens on standing: the most likely conditions are
Correct Answer: Alkaptonuria
Description: The urine of alkaptonuric patients becomes dark after being exposed to air.
In presence of oxygen, the colorless homogentisate (homogentisic acid) undergoes spontaneous oxidation to yield benzoquinone acetate, which polymerizes to form black-brown pigment alkapton.
Alkapton imparts a characteristic black-brown colour to urine.
Category:
Biochemistry
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now