As an example of condensation reactions, consider that in living organisms, Amino acids are condensed with one another by an enzyme to form amide linkages (known as peptides). The resulting polyamides are known as proteins or polypeptides. In the diagram below, consider the amino-acids as single aliphatic monomers reacting with identical molecules to form a polyamide, focusing on solely the amine and acid groups. Ignore the substituent R groups – under the assumption the difference between the R groups are negligible: