Which type of biomolecules have some structural similarity with synthetic polyamides? What is this similarity?

(N/A) Proteins are the biomolecules that show structural similarity with synthetic polyamides.
Synthetic polyamides contain repeating amide linkages $(-CONH-)$ in their backbone.
Similarly,proteins are polypeptides formed by the condensation of amino acids,which also contain repeating amide linkages known as peptide bonds $(-CONH-)$ in their structure.