Lack of Homogentisate oxidase enzyme causes
Phenylketonuria
Alkaptonuria
Maple syrup urine disease
Homocystinuria
(B) Alkaptonuria # ALKAPTONURIA: The defective enzyme in alkaptonuria is homogentisate oxidase in tyrosine metabolism. Homogentisate accumulates in tissues & blood, gets oxidized to the corresponding quinones, which polymerize to give black or brown colour. For this reason, the urine of alkaptonuric patients resembles coke in colour.
Miscellaneous (Bio-Chemistry)