(Also polypeptide). Biochemical formed by the linkage of up to about 50
amino acids to form a chain. Longer chains are called
proteins. The
amino acids are coupled by a peptide bond, a special linkage in which the nitrogen atom of one amino acid binds to the carboxyl carbon atom of another. Many peptides, such as the hormones vasopressin and ACTH, have physiological or antibacterial activity. See also
Amino Acids.