BIOL 121 Lecture Notes - Lecture 23: Arteriole, Reversible Reaction, Globin
Document Summary
Immature rbcs contain a nucleus, but once mature and circulating the blood, they don"t. It is in the immature form that the nucleus directs the production of hemoglobin by the cell. Once mature and circulation, no more hemoglobin can be produced. The average human male has a total of roughly 900gm (2 pounds) of hemoglobin. Roughly 0. 3gm are produced every hour while 0. 3gm are destroyed. Each rbc contains roughly 29 pg of hemoglobin. Each molecule of hemoglobin contains 4 subunits. Each subunit contains a single heme molecule attached to a polypeptide. Combines, the 4 polypeptides are called globin. Each heme molecule can carry one oxygen atom attached to the central iron atom. Therefore, each hemoglobin molecule can carry 4 oxygen molecules. It is this iron atom that gives each red blood cell, and hence blood, its red color. When the blood leaves the lungs after picking up oxygen, the hemoglobin is almost completely saturated with oxygen.
