PATHOLOGY

Detailed explanation-1: -The hemoglobin molecule has four binding sites for oxygen molecules: the iron atoms in the four heme groups. Thus, each Hb tetramer can bind four oxygen molecules. From the molecular weight of Hb, one can calculate that 1 g of Hb can combine with 1.39 ml of oxygen.

Detailed explanation-2: -Each heme group surrounds an atom of iron, and each iron atom can loosely bind an oxygen atom. Binding up to four oxygen molecules, the hemoglobin forms the compound called oxyhemoglobin.

Detailed explanation-3: -The mammalian hemoglobin molecule can bind (carry) up to four oxygen molecules.