Lexic.us

Definition of Phenylalanine

1. Noun. 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.

Definition of Phenylalanine

1. Noun. (amino acid) An essential amino acid C₉H₁₁NO₂ found in most animal proteins; it is essential for growth; the inability to metabolize it leads to phenylketonuria; it is a constituent of aspartame. ¹

¹ Source: wiktionary.com

Definition of Phenylalanine

1. [n -S]

Medical Definition of Phenylalanine

1. 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. (15 Oct 1997)

Lexicographical Neighbors of Phenylalanine

Literary usage of Phenylalanine

Below you will find example usage of this term as found in modern and/or classical literature:

1. Oxidations and Reductions in the Animal Body by Henry Drysdale Dakin (1922)
"The naturally occurring aromatic amino acids, derived from proteins, phenylalanine, tyrosine and tryptophan, however, readily undergo oxidation which ..."

2. Practical physiological chemistry by Philip Bovier Hawk (1918)
"Phenylalanine has been obtained from all the proteins examined except from the pro- tamines and ... The crystalline form of phenylalanine is shown in Fig. ..."

3. Practical physiological chemistry: A Book Designed for Use in Courses in by Philip Bovier Hawk (1916)
"Phenylalanine has been obtained from all the proteins examined except from the pro- tamines and ... The crystalline form of phenylalanine is shown in Fig. ..."

4. The Chemical Constitution of the Proteins by Robert Henry Aders Plimmer (1908)
"Those proteins, such as gelatin, in which its presence was demonstrated by Spiro, and which contains no tyrosine, was found to contain phenylalanine as its ..."

5. The Chemical Constitution of the Proteins by Robert Henry Aders Plimmer (1917)
"The ester of phenylalanine differs from the esters of aspartic acid, ... If a large amount of phenylalanine be present, it may separate in the form of oily ..."

6. Food Chemicals Codex: First Supplement to the Fifth Edition by Committee on Food Chemicals Codex, Institute of Medicine (U. S.) (2006)
"phenylalanine Reference Standard, accurately weighed, into a 100-mL volumetric flask, and dilute to volume with Mobile Phase. ..."

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