protein

A polymer of amino acids linked via peptide bonds and which may be composed of two or more polypeptide chains. (See Polypeptide.)

A macromolecule composed of one or more polypeptides, each comprising a chain of amino acids linked by peptide bonds.

A large molecule composed of one or more chains of amino acids in a specific order. The order is determined by the base sequence of nucleotides in the gene that codes for the protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs; and each protein has unique functions. Examples are hormones, enzymes, and antibodies.

(PRO-teen) A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

A large complex molecule made up of one or more chains of amino acids. Proteins perform a wide variety of activities in the cell. See also cell, gene

A large molecule composed of one or more chains of amino acids in a specific order; the order is determined by the base sequence of nucleotides in the gene that codes for the protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs; and each protein has unique functions. Examples are hormones, enzymes, and antibodies.

A protein molecule is a chain of up to several hundred amino acids and is folded into a more or less compact structure. Because about 20 different amino acids are used by living matter in making proteins, the variety of protein types is enormous. In their biologically active states, proteins function as catalysts in metabolism and to some extent as structural elements of cells and tissues. Protein content in biomass (in mass %) can be estimated by multiplying the mass % nitrogen of the sample by 6.25. (Source: Biofuels Glossary. September 1986. Solar Technical Information Program, Solar Energy Research Institute.)