Essential Biochemistry - Protein Metabolism (Section 8 - No. 2)

Which vitamin is required for the hydroxylation of phenylalanine to tyrosine?

Vitamin B6

Vitamin B12

Vitamin C

Tetrahydrobiopterin (BH4)

The hydroxylation of phenylalanine to tyrosine requires tetrahydrobiopterin (BH4) as a cofactor.