I have used a telephone “Handset Coil Cord” as a simple and convenient model for the structure of a polypeptide. When the ends are distinguished, the cord itself represents the linear sequence of the amino acids (the primary structure); the coiled nature of the cord can represent the common α-helical conformation of a polypeptide chain (the secondary structure); and the folding of the coil approximates the tertiary structure that is found in many globular proteins.