Definition

1. Noun:
   • A biological macromolecule: Any of a large group of complex, nitrogenous organic compounds that are essential constituents of all living cells. They consist of one or more long chains of amino acids and are crucial for the structure, function, and regulation of the body's tissues and organs.
   • A dietary nutrient: A substance found in food (such as meat, eggs, milk, and legumes) that is necessary in the diet of animals for growth, repair of tissues, and overall bodily maintenance.

Usage and Examples

• As a noun (general substance):
  • Muscle tissue is primarily composed of protein.
  • Enzymes, which catalyze biochemical reactions, are a type of protein.
• As a noun (dietary component):
  • Athletes often increase their protein intake to support muscle recovery.
  • This nutritional label shows the amount of protein per serving.

Advanced Usage and Context

• "Complete protein": A food source that contains all nine essential amino acids that the human body cannot synthesize on its own. Animal products are typically complete proteins.
  • Quinoa and soy are rare plant-based sources of complete protein.
• "Protein synthesis": The cellular process of building proteins from amino acids, directed by genetic code.
  • Ribosomes are the sites of protein synthesis in a cell.

Variants and Related Words

• Protease (n): An enzyme that breaks down proteins into smaller polypeptides or amino acids.
• Proteinaceous (adj): Of, relating to, or resembling protein.
  • The virus has a proteinaceous coat.

Synonyms

• Macromolecule: A very large molecule, such as a protein, polymer, or nucleic acid.
• Polypeptide: A linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule.

Related Phrases and Compounds

• Protein shake: A beverage made by mixing protein powder with liquid, often consumed for dietary supplementation.
  • She drinks a protein shake after her workout.
• Protein deficiency: A state of nutritional lack of adequate proteins, which can lead to health issues like kwashiorkor.
  • The doctor was concerned about signs of protein deficiency.

Idioms and Figurative Use

Note: "Protein" is a scientific and nutritional term. It is not commonly used in idiomatic expressions. Its usage is almost exclusively literal, referring to the biochemical compound or nutrient.

Noun

1. any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes
   • a diet high in protein