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

They used both observational data and genetic techniques to assess whether blood levels of phenylalanine and tyrosine were related to overall mortality and predicted lifespan.

From Science Daily • Feb. 26, 2026

This strengthens the possibility that tyrosine itself may independently influence aging.

From Science Daily • Feb. 26, 2026

Their findings suggest that higher tyrosine levels are associated with shorter life expectancy in men, raising the possibility that longevity strategies may need to differ by sex.

From Science Daily • Feb. 26, 2026

However, after deeper analysis, only tyrosine showed a consistent and potentially causal relationship with reduced life expectancy in men.

From Science Daily • Feb. 26, 2026

Hydrolysis by acids indicates that it contains leucine and tyrosine, two amino-acids which are constituents of proteins, along with other bodies of unknown composition.

From The Chemistry of Plant Life by Thatcher, Roscoe Wilfred