• Aug 20, 2025 Protein Backbone two amino acids, glycine (Gly) and alanine (Ala). The carboxyl group of Gly reacts with the amino group of Ala, forming a peptide bond and creating a dipeptide: Gly-Ala. The continuation of this process with many amino acids results in a polypeptide chain. 3. The Backbone By Myriam Swift