Amides, Imides and Peptides

PROTEIN chemistry has its origins in physiology. For the last half-century the group formed by condensing the carboxyl group of an amino-acid with the amino group of another amino-acid has been called a peptide group, and the long molecule formed by condensing a number of amino-acids, a poly-peptide. Protein molecules contain numerous peptide links (—CO.NH—) in the backbone of the molecule; they also in most cases carry amido groups (—CO.NH2) as terminal groups of certain of their side-chains.