The peptide bond
(a) A polypeptide is formed by the removal of water between amino acids to form peptide bonds. Each aa indicates an amino acid. R1, R2, and R3 represent R groups (side chains) that differentiate the amino acids. (b) The peptide bond is a rigid planar unit with the R groups projecting out from the C–N backbone. Standard bond distances (in angstroms) are shown.

ANIMATED ART: Translation: peptide-bond formation