How does the enzyme phenylalanine hydroxylase play a crucial role in the metabolism of the amino acid phenylalanine, and what is the consequence of its deficiency?

A It converts phenylalanine to tyrosine, and its deficiency leads to albinism
B It converts phenylalanine to tyrosine, and its deficiency leads to phenylketonuria (PKU) ✓
C It converts tyrosine to phenylalanine, and its deficiency leads to alkaptonuria
D It converts tryptophan to serotonin, and its deficiency leads to depression

Explanation

Phenylalanine hydroxylase is an enzyme that catalyzes the conversion of phenylalanine to tyrosine. Its deficiency leads to the accumulation of phenylalanine in the body, causing phenylketonuria (PKU), a genetic disorder that can lead to intellectual disability if left untreated.

Source

Biochemistry textbook by Jeremy M. Berg
Enzymes in Disease Biochemistry Amino Acid Metabolism Disorders Medium MEDICAL Confidence: high