pro·tein
| \ ˈprō-ˌtēn
also ˈprō-tē-ən
\
also ˈprō-tē-ən
\
Definition of protein
1
: any of various naturally occurring extremely complex substances that consist of amino-acid residues joined by peptide bonds, contain the elements carbon, hydrogen, nitrogen, oxygen, usually sulfur, and occasionally other elements (such as phosphorus or iron), and include many essential biological compounds (such as enzymes, hormones, or antibodies)
2
: the total nitrogenous material in plant or animal substances
Examples of protein in a Sentence
You need more protein in your diet.
These foods are an excellent source of protein.
These foods have all of the essential proteins.
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Recent Examples on the Web
Those proteins are able to sensitize the immune system and trigger an allergic reaction in someone with a food allergy. — Jennifer Couzin-frankel, Science | AAAS, "Can antacids boost allergy risk?," 30 July 2019 Far from biologically irrelevant, the proteins are perhaps critical to the health of the reef ecosystem and its ability to respond to stress. — Smithsonian, "Amazing Photos Reveal the Hidden Light of Undersea Life," 25 July 2019 Non-animal whey protein is new and may require scrutiny by the U.S. Food and Drug Administration. — Larissa Zimberoff, latimes.com, "Here comes lab-grown dairy: milk proteins made without animals," 11 July 2019 Resource interests, food security, water, protein, fishing rights, maritime trade routes, mining interests — issues that span the planet — are the baseline interests for China’s billion-plus people. — Jonathan D. T. Ward, National Review, "China and the Major Powers," 25 June 2019 Currently, Impossible protein is only available at the Chandler Boulevard location. — Ava Garcia, azcentral, "Your guide to fast food restaurants with Beyond and Impossible burgers in metro Phoenix," 24 June 2019 Furthermore, the researchers showed that a protein required for viral replication was present in cells that did not have the genome segment coding for it. — Quanta Magazine, "Viruses Can Scatter Their Genes Among Cells and Reassemble," 21 May 2019 Milk, according to food chemists, is a liquid combination of fat, protein, enzymes, vitamins, and sugar produced by mammals to nourish their offspring. — Umair Irfan, Vox, "“Fake milk”: why the dairy industry is boiling over plant-based milks," 31 Aug. 2018 In addition, the fact that there were only two telomeres means that the proteins that normally shut nearby genes were present in excess, allowing the gene-shutdown effect to spread further from the two telomeres that remained. — John Timmer, Ars Technica, "Gene editing crunches an organism’s genome into single, giant DNA molecule," 3 Aug. 2018These example sentences are selected automatically from various online news sources to reflect current usage of the word 'protein.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
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More Definitions for protein
protein
noun
English Language Learners Definition of protein
: a substance found in foods (such as meat, milk, eggs, and beans) that is an important part of the human diet
See the full definition for protein in the English Language Learners Dictionary
protein
noun
pro·tein
| \ ˈprō-ˌtēn
\
\
Kids Definition of protein
: a nutrient found in food (as meat, milk, eggs, and beans) that is made up of many amino acids joined together, is a necessary part of the diet, and is essential for normal cell structure and function
pro·tein
| \ ˈprō-ˌtēn
, ˈprōt-ē-ən
\
, ˈprōt-ē-ən
\
Medical Definition of protein
1
: any of numerous naturally occurring extremely complex substances (as an enzyme or antibody) that consist of amino acid residues joined by peptide bonds, contain the elements carbon, hydrogen, nitrogen, oxygen, usually sulfur, and occasionally other elements (as phosphorus or iron), that are essential constituents of all living cells, that are synthesized from raw materials by plants but assimilated as separate amino acids by animals, that are both acidic and basic and usually colloidal in nature although many have been crystallized, and that are hydrolyzable by acids, alkalies, proteolytic enzymes, and putrefactive bacteria to polypeptides, to simpler peptides, and ultimately to alpha-amino acids
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