So let's suppose we have the following five amino acid polypeptide. So let's begin on the left side. So we have amino acid number one. Then we have a peptide bond shown in green. We have amino acid number two, a second peptide bond, amino acid number three, a third peptide bond, amino acid number four, a fourth peptide bond, and amino acid number five. And these amino acids in a polypeptide are also known as residues.