Hemoglobin has a molecular mass of 64,500 grams per mole with four iron atoms in each molecule. Molecular mass refers to the mass of a mole of substance expressed in grams per mole.
Hemoglobin is a red blood cell component that helps in transporting oxygen from the respiratory organs to the tissues of the body. This oxygen burns nutrients in the tissues to produce energy for the body. It also transports carbon dioxide back to the lungs. Besides the red blood cell, hemoglobin is also found in the progenitor lines. It has four units that each have a globin polypeptide chain bounded to an iron with heme molecule.