- Hemoglobin, the oxygen-carrying component of RBCs, is composed of two pairs of protein chains called globin and four smaller units called heme, which contain iron. Iron binds and releases oxygen (O2).
- Decreases in hemoglobin reduce the amount of O2 carried by the blood to cells. The oxygen-carrying capacity of hemoglobin can be affected by the formation of gases that can prevent O2 from reaching cells and by abnormalities of hemoglobin production and destruction.
Hemoglobin Molecule
