leucine

American  

[loo-seen, -sin] / ˈlu sin, -sɪn /

noun

Biochemistry.

1. a white, crystalline, water-soluble amino acid, C 6 H 13 NO 2 , obtained by the decomposition of proteins and made synthetically: essential in the nutrition of humans and animals. Leu; L

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leucine British  

/ ˈluːsɪn, ˈluːsiːn /

noun

1. an essential amino acid found in many proteins

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leucine Scientific  

/ lo̅o̅′sēn′ /

1. An essential amino acid. Chemical formula: C ₆ H ₁₃ NO ₂ .

2. See more at amino acid

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Etymology

Origin of leucine

First recorded in 1820–30; leuc- + -ine ¹

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Compare meaning

How does leucine compare to similar and commonly confused words? Explore the most common comparisons:

• isoleucine vs. leucine

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Example Sentences

See Examples For:

leucine

Amino acids are the building blocks used to make proteins, and leucine is especially abundant in protein rich foods such as dairy products, meat, beans, and lentils.

From Science Daily ● Oct. 3, 2026

In this case, leucine appears to help cells adjust energy production according to nutrient availability by protecting key mitochondrial proteins from degradation.

From Science Daily ● Oct. 3, 2026

In the worms, problems with leucine breakdown disrupted mitochondrial function and were linked to fertility problems.

From Science Daily ● Oct. 3, 2026

That observation could be important for future cancer research because treatments that alter leucine related pathways may affect both healthy cells and tumor cells in different ways.

From Science Daily ● Oct. 3, 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 Roscoe Wilfred Thatcher

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