QuestionSBA
QuestionChoice
The condition described here is phenylketonuria (PKU), which is associated with high phenylalanine levels. Methionine (Met) is not involved in PKU.
10003835
e
Methionine
QuestionChoice
The condition described here is phenylketonuria (PKU). Tyrosine (Tyr) is an incorrect answer. Tyrosine is the amino acid that phenylalanine is normally converted to by phenylalanine hydroxylase. This is reduced or absent in PKU. In PKU, tyrosine often needs supplementation as less is produced.
10003832
b
Tyrosine
QuestionChoice
The condition described here is phenylketonuria (PKU), which is associated with high phenylalanine levels. Proline (Pro) is not involved in PKU.
10003834
d
Proline
QuestionChoice
The condition described here is phenylketonuria (PKU), which is associated with high phenylalanine levels. Cysteine (Cys) is not involved in PKU.
10003833
c
Cysteine
QuestionChoice
The condition described here is phenylketonuria (PKU). This is an autosomal recessive condition, and the main issue is the accumulation of the amino acid phenylalanine which is toxic to the brain. The three-letter code for phenylalanine is Phe.
10003831
a
Phenylalanine
Concept
Chapter
2693
4206
Amino acids
Topic
180
Biochemistry
13313
A 5-day-old infant receives a heel prick test. The test comes back positive for an inherited metabolic disease.

The paediatrician informs the parents that, if left untreated, the infant may suffer from developmental delay, seizures, motor deficits and psychiatric issues amongst other consequences. The paediatrician also informs the parents that the child will have to follow a lifelong restrictive diet.

Which of the following amino acids is high in this condition?
a