polypeptide

This term describes the chemical precursor to a functional protein. While a peptide is a short chain, a polypeptide is a long, extended string of amino acids. It represents the primary structure of a protein before it folds into a complex three-dimensional shape. In a laboratory or medical context, the word evokes a sense of raw biological building blocks. It is a technical term used in biochemistry and molecular biology to distinguish the simple chemical chain from the biologically active, folded protein.