http://www.ck12.org Chapter 26. Biochemistry
FIGURE 26.8
Hemoglobin molecule.FIGURE 26.9
Oxygen binding to iron in hemoglobin.When the oxygen binds to the iron, the three-dimensional shape of the molecule changes. Upon release of the
oxygen to the cells, the shape changes back.
Some individuals have a specific mutation in the primary sequence of their hemoglobin molecules that causes them
to aggregate, resulting in a deformation of their red blood cells. This abnormality is genetic in nature. A person may
inherit the gene from one parent and have sickle cell trait (only some of the hemoglobin is hemoglobin S), which is
usually not life-threatening. Inheriting the gene from both parents will result in sickle cell disease, which is a very
serious condition.