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.
Recent Examples of protein from the Web
Where most regions are best known for one, maybe two, different cuts or proteins, Kansas City offers a bit of everything: pork, beef, chicken, lamb, mutton, and yes, even fish.
The mutations produce proteins recognized by the immune system as foreign and ripe for attack, and the drug boosts the system's response.
Many state governments have criticized the ban as a blow to beef and leather exports that will leave hundreds of thousands jobless and deprive millions of Christians, Muslims and poor Hindus of a cheap source of protein.
Out comes DNA, RNA, protein drugs and viral particles — rapidly and without human intervention.
Many state governments criticized the ban as a blow to beef and leather exports that will leave hundreds of thousands jobless and deprive millions of Christians, Muslims and poor Hindus of a cheap source of protein.
Ms. Adewunmi, 34, cooks for ease when fasting, focusing on carbohydrates and protein, often preparing a single, simple recipe on a loop all month.
In the trial, a patient’s T cells, which are part of the immune system, were extracted from the blood and genetically modified to recognize a specific protein on cancer cells.
As neighborhood butcher shops have gone the way of the compact disc, the mass production of protein has devolved into something creepily assembly-lined and abstract.
These 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.
Origin and Etymology of protein
French protéine, from Late Greek prōteios primary, from Greek prōtos first — more at prot-
First Known Use: 1886
PROTEIN Defined for English Language Learners
Definition of protein for English Language Learners
: a substance found in foods (such as meat, milk, eggs, and beans) that is an important part of the human diet
PROTEIN Defined for Kids
Definition of protein for Students
: 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
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
2: the total nitrogenous material in plant or animal substances; especially : crude protein
Seen and Heard
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