Chemistry - Biomolecules Question with Solution | TestHub

When a protein is made up of two or more than two polypeptide held together variously than it form quaternary structure. Protein haemoglobin has quaternary structure as it is made up of 4 polypeptide or subunits. Two of these are identical to each other. Hence two subunits of alpha type and two subunits of beta type together constitutes the human haemoglobin molecule.