Question

Which structure changes when a chemical disrupts the ionic bond connecting 2 polypeptides? Primary, tertiary, secondary or quarternary structure of the protein?

Answer 1

the primary structure of the protein is the stretch of amino acids linked by peptide bonds, the main secondary structures found in the proteins beta sheets and alpha helices both are formed by the hydrogen bond between the oxygen atom of the carbonyl carbon and the hydrogen of the amino group. the tertiary structure is formed by different interactions like Vander Waals interactions, hydrogen bonds, hydrophobic interactions, ionic bonds, etc.

proteins with a quarternary structure have multiple subunits that are linked by hydrogen bonds, hydrophobic interactions, ionic bonds, disulphide bonds etc.

here there are 2 polypeptides so each polypeptide may be forming different subunits of the protein so the chemical disrupts the ionic bond connecting 2 polypeptides disrupt the quarternary structure.