- protein - 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"
--1 is a kind of macromolecule, supermolecule
--1 is a substance of meat; egg, eggs; milk; legume
--1 has substances: amino acid, aminoalkanoic acid; polypeptide
--1 has particulars: