What is the molecular composition of hemoglobin? Does the functionality of hemoglobin as a protein depend upon its tertiary or upon its quaternary structure?
Hemoglobin is a molecule made of four polypeptide chains, each bound to an iron-containing molecular group known as a heme group. So the molecule contains four polypeptide chains and four heme groups.
As a protein composed of association of polypeptide chains, the functionality of hemoglobin depends upon the integrity of its quaternary structure.
Blood Questions - Image Diversity: hemoglobin molecule