The Red Blood Cell

Hemoglobin can’t circulate in the blood freely on its own—that is not a physiologically viable option. It must be sequestered inside a cell dedicated to containing and preserving it: the red blood cell. Red cells and their precursors in the bone marrow produce hemoglobin, are the source of 2,3-biphosphoglycerate that assures optimal positioning of the hemoglobin-oxygen dissociation curve, have enzymes that prevent oxidation of heme iron, and generate energy to maintain red cell deformability to assure optimal oxygen delivery in the microcirculation. Red cell production and iron transport are carefully regulated; at the end of the red cell’s lifespan, its components are broken down and recycled or disposed of.