Phenylalanine

Phenylalanine is an amino acid that is used in the biosynthesis of proteins. It is essential in humans, meaning the body cannot synthesize it and thus it must be obtained from the diet. Phenylalanine is a direct precursor to the neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), collectively known as the catecholamines.

Structure

Phenylalanine is a monocyclic aromatic amino acid, a family that includes tyrosine and tryptophan. The molecule is composed of a benzyl side chain, a carboxyl group, and an amino group.

Functions

Phenylalanine plays an integral role in the structure and function of proteins and enzymes and the production of other amino acids. It is also crucial in the production of chemical messengers required for brain function.

Dietary Sources

Phenylalanine is found in most protein-rich foods including beef, poultry, pork, fish, milk, yogurt, eggs, cheese, soy products, and certain nuts and seeds.

Health Effects

Phenylalanine is used in the body to produce tyrosine, another amino acid that's needed for specific brain functions. It's also used to produce chemical messengers, but it's not clear whether this improves mood or mental function.

See Also

• Amino acid
• Protein biosynthesis
• Neurotransmitter
• Dopamine
• Norepinephrine
• Epinephrine
• Catecholamines
• Tyrosine
• Tryptophan