text: D-C-C and BOP ["bop"] are commonly used to couple these compounds.
full_question: D-C-C and BOP ["bop"] are commonly used to couple these compounds. Polystyrene resins are used as support in a synthesis using these compounds pioneered by Robert Merrifield. The dihedral angles of these compounds are shown on a Ramachandran plot. Reacting an aldehyde with cyanide, then hydrolyzing the product produces one of these compounds in the Strecker synthesis. At biological pH these compounds exist in a zwitterionic form. Examples of these compounds include tryptophan and glycine. These compounds contain an NH2 as well as a carboxyl group. For 10 points, name these monomers that are linked together by peptide bonds in proteins.
first_sentence: D-C-C and BOP ["bop"] are commonly used to couple these compounds.
raw_answer: amino acids [prompt on "peptides", "polypeptides" or "amides" until "Ramachandran" is read]