Proteins and peptides are among the most exquisite examples of hosts/guests for molecular recognition. Composed of amino acid building blocks, peptides are highly flexible and structurally promiscuous, switching between multiple structures (random/strand/sheet/turn/helical) in solution. Peptides pay a significant entropy penalty to organize into the one structure recognised by a biological receptor and responsible for activity. We are developing new macrocycles, composed of molecular constraints and amino acids, organized into specific strand, turn, or helical shapes. These building blocks are more structured, more chemically stable, and have higher receptor affinities than peptides enabling potential uses as new biological tools, drug leads, catalysts, devices or new materials.''