tyrosine

American  

[tahy-ruh-seen, -sin, tir-uh-] / ˈtaɪ rəˌsin, -sɪn, ˈtɪr ə- /

noun

Biochemistry.

1. a crystalline amino acid, HOC 6 H 4 CH 2 CH(NH2 )COOH, abundant in ripe cheese, that acts as a precursor of norepinephrine and dopamine. Tyr; Y

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tyrosine British  

/ -sɪn, ˈtɪrə-, ˈtaɪrəˌsiːn /

noun

1. an aromatic nonessential amino acid; a component of proteins. It is a metabolic precursor of thyroxine, the pigment melanin, and other biologically important compounds

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tyrosine Scientific  

/ tī′rə-sēn′ /

1. A nonessential amino acid. Chemical formula: C ₉ H ₁₁ NO ₃ .

2. See more at amino acid

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Etymology

Origin of tyrosine

1855–60; < Greek tȳrós cheese + -ine ²

Example Sentences

See Examples For:

tyrosine

The findings suggested that higher tyrosine levels may contribute to reduced life expectancy in men.

From Science Daily ● Jun. 15, 2026

Phenylalanine and tyrosine are two amino acids that help regulate metabolism and brain activity.

From Science Daily ● Jun. 15, 2026

The researchers also noted that men generally have higher tyrosine levels than women, which may help explain part of the long observed difference in average lifespan between the sexes.

From Science Daily ● Jun. 15, 2026

Because of these functions, tyrosine has attracted growing interest among researchers studying aging, brain health, and lifespan.

From Science Daily ● Jun. 15, 2026

It is also found in horse’s liver, being one of the putrefaction products of tyrosine.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 6 "Coucy-le-Château" to "Crocodile" by Various