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.
See More
Recent Examples on the Web
Indeed, Yuan had identified a monkeyflower protein that might serve as the activator. — Elizabeth Pennisi, Science | AAAS, "Meet the monkeyflower, a weed that may hold the key to zebra stripes and other biological mysteries," 29 Aug. 2019 Also try the chicken nuggets that, by the way, aren't actually chicken nuggets — rather, they're made of a vegetarian protein that comes from a mushroom. — Emily Sabens, Indianapolis Star, "Kid-friendly restaurants: 9 places in Indianapolis with the best children's menus," 29 Aug. 2019 The drug clears a toxic brain protein called beta amyloid believed to trigger the disease. — San Diego Union-Tribune, "No cure yet, but progress made in managing and detecting Alzheimer’s," 26 Aug. 2019 There’s a gene, FLG, that makes a protein that helps build the skin’s barrier function. — Scientific American, "Researchers Optimistic About Breaking Stride Of The Atopic March," 26 Aug. 2019 Hemocyanin is a protein similar to hemoglobin that transports oxygen through the body. — Caren Chesler, Popular Mechanics, "The Blood of the Crab," 23 Aug. 2019 Not only that, the scientists also found that damage to brain regions involved in daytime wakefulness was caused by a protein called tau. — chicagotribune.com, "Too much napping may signal Alzheimer’s," 22 Aug. 2019 As a protein fallback, there were always warm nuts in the bar, part of a daylong panoply of food and drink. — Los Angeles Times, "On Canada’s Via Rail, a return to the older — and let’s be honest, better — way of traveling," 17 Aug. 2019 Pangolin scales are made of nothing more than keratin, a protein that makes up fingernails, hair, horns, claws, and hooves. — National Geographic, "Pangolin scales are not a party drug, say researchers," 9 Aug. 2019These 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.
Keep scrolling for more
Keep scrolling for more
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
Keep scrolling for more