phenylalanine

[(Science: amino acid) One of the amino acids which the body cannot manufacture itself, but must acquire from food. It is abundant in meats and cheese. Phenylalanine is a precursor of tyrosine and together they lead to the formation of thyroxine or thyroid hormone and of adrenaline and noradrenaline which is converted into a neurotransmitter, a brain chemical which transmits nerve impulses. This neurotransmitter is used by the brain to manufacture noradrenaline which promotes mental alertness, memory, elevates mood and suppresses the appetite very effectively. Along with another amino acid, tryptophan, phenylalanine governs the release of an intestinal hormone called cholecystokinin. Overuse of phenylalanine supplements can cause anxiety, headaches and hypertension and are contraindicated for pregnant woman, those who suffer from anxiety attacks, high blood pressure, pKU, pigmented melanoma or anyone taking an anti-depressant containing monoamine oxidase inhibitors. An essential amino acid found in proteins and needed for growth of children and for protein metabolism in children and adults; abundant in milk and eggs; it is normally converted to tyrosine in the human body.A type of [[amino acid commonly found in [[proteins.