Question

which enzyme deficiency is responsible for the accumulation of homogentisic acid in ochronosis?
tyrosinase
homogentisic acid oxidase
alkapton reductase
phenylalanine hydroxylase

Explanation:

In ochronosis, the accumulation of homogentisic acid is due to a deficiency of homogentisic acid oxidase. This enzyme is involved in the tyrosine - metabolism pathway, and its deficiency leads to an inability to break down homogentisic acid, causing its accumulation.

Answer:

B. Homogentisic acid oxidase