Medically reviewed by Aviv Joshua, MS, RDN Phenylalanine is an essential amino acid (building block of protein) that the body doesn't produce, meaning it must be obtained through food. It is found in ...

The present work was carried out, using phenylalanine labelled with carbon-14, to examine whether phenylalanine is a precursor of tyrosine.

Phenylalanine is metabolized to produce maleylacetoacetate in a four-step biochemical reaction. Absence of the enzyme homogentisate oxidase causes the buildup of homogentisate, leading to the ...