This invention discloses short chain peptides that have been constrained to adopt an alpha helical conformation and their use as alpha helical scaffolds for directing amino acid side chains into positions analogous to those found in longer chain alpha helical peptides and for attaching peptidic or non-peptidic appendages in order to mimic side chains of longer alpha helical peptides. More particularly the invention discloses alpha helical cyclic pentapeptides and their use as alpha helical scaffolds or macrocyclic alpha helical modules, either alone, or within longer chain peptides or attached to other macrocyclic peptides or attached to non-peptidic structures, for the purpose of mimicking naturally occurring peptides or proteins, and as agonists or antagonists of the biological activity of naturally-occurring peptides or proteins or for the preparation of new materials.