Answer :
Both myoglobin and Hemoglobin contain a heme prosthetic group with a Iron atom in the center. Unlike hemoglobin, which is comprised of both alpha and beta globin polypeptides, myoglobin is a monomer, thus is lacks Quaternary structure.
Explanation:
The Heme group provides the ability to connect oxygen to myoglobin and hemoglobin due to the existence of an iron atom. It also corresponds to the red color contained in blood and muscles. That faction of hemes includes an iron atom, which can bind to one molecule of oxygen.
Myoglobin is a monomer therefore it has no quaternary structure at all. Myoglobin binds more strongly to oxygen than hemoglobin does. The variation in binding energy represents the transfer of oxygen from the bloodstream, from hemoglobin to myoglobin, into cells.