Question

In order to lessen the suffering of phenylketonurics their diet should have

• A. no phenylalanine and no tyrosine
• B. low phenylalanine and normal requirement of tyrosine
• C. normal recommended amount of phenylalanine
• D. normal recommended amount of both phenylalanine and tyrosine

Answer 1

Answer: (B)

Phenylketonuria $(PKU)$ is a disease caused by the livers inability to produce a particular type of phenylalanine hydroxylase $(PAH)$ enzyme. This enzyme converts the amino acid phenylalanine into tyrosine. A lack of $PAH$ causes buildup of abnormally high phenylalanine concentrations in the blood and brain. The typical diet prescribed for $PKU$ patients is very small amount of phenylalanine and higher quantity of tyrosine.