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noun Common

protein

PROH-tee-ihn

Protein (noun) means a large biological molecule made of chains of amino acids, essential to the structure and function of living cells. Example: “Muscles are largely built from protein.”

noun
1
A large biological molecule made of chains of amino acids, essential to the structure and function of living cells.
"Muscles are largely built from protein."
"The enzyme is a protein that speeds up digestion."
2
Food that is a major source of this nutrient, especially meat, fish, eggs, or legumes.
"Try to include some protein with every meal."

How to use protein

Learner’s notes

In plain EnglishOne of the body's essential building blocks, found in foods like meat, eggs, and beans, and in every living cell.

Common pairings
protein source high in protein protein shake

Word forms

proteins plural

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Test yourself on “protein” A quick quiz — meaning, synonyms & usage

Fill the gap

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Muscles are largely built from _____.

Etymology

Coined from Greek prōteîos ("primary, of first importance") by chemist Jöns Jacob Berzelius, suggesting these molecules are fundamental to life.

Origin: Greek

Rhymes for protein

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Frequently asked questions

What does “protein” mean?

The word “protein” means a large biological molecule made of chains of amino acids, essential to the structure and function of living cells. In plain terms, one of the body's essential building blocks, found in foods like meat, eggs, and beans, and in every living cell.

How do you pronounce “protein”?

“Protein” is pronounced PROH-tee-ihn (/ˈpɹoʊ.tiːn/ in IPA).

How do you use “protein” in a sentence?

Here is “protein” used in a sentence: “Muscles are largely built from protein.”

What part of speech is “protein”?

“Protein” is a noun.

Where does the word “protein” come from?

The word “protein” comes from Greek. Coined from Greek prōteîos ("primary, of first importance") by chemist Jöns Jacob Berzelius, suggesting these molecules are fundamental to life.

Is “protein” a common word?

“Protein” is a fairly common word in modern English.

How many meanings does “protein” have?

“Protein” has 2 distinct senses listed in this dictionary. The most common is: a large biological molecule made of chains of amino acids, essential to the structure and function of living cells.

What is the difference between a protein and an amino acid?

Amino acids are the small building blocks; proteins are the large molecules built from them. Chains of amino acids fold into a protein, much as letters combine into words. There are about twenty common amino acids, and the order in which they link determines the shape and job of the finished protein.

Why is protein important?

Protein is essential to the structure and function of every living cell. It builds and repairs muscle, skin and tissue, forms enzymes that drive chemical reactions, carries oxygen in the blood, and supports the immune system. Because the body cannot store it the way it stores fat, a steady dietary supply matters.

What are the types of protein?

Proteins can be grouped by their job. Structural proteins like collagen and keratin give tissues their shape and strength. Enzymes speed up reactions, hormones such as insulin send signals, antibodies defend against infection, and transport proteins like haemoglobin move substances around the body. All are built from the same amino-acid chains.

What foods are high in protein?

Protein is found in both animal and plant foods. Meat, fish, eggs and dairy are rich, complete sources containing all the essential amino acids. Plant sources include beans, lentils, tofu, nuts and grains, which can be combined to cover the full range. These foods supply the amino acids the body needs.

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