A typical human erythrocyte (red blood cell) contains about 270 million haemoglobin molecules, near each carrying four heme groups.
Decrease of hemoglobin, near or without an total decrease of red blood cell, leads to symptoms of anemia. Anemia have many different cause, although iron deficiency and its resultant iron less anemia are the most common cause in the Western world. As malingering of iron decreases heme synthesis, red blood cell in iron not as much as anemia are hypochromic (lacking the red hemoglobin pigment) and microcytic (smaller than normal).
4 heme molecules
four.