Biconcave disc characteristic red color and transport oxygen from the lungs to the tissues. Mature red blood cells are round and biconcave because they lack a nucleus and unlike other cells, red cells require a small amount of oxygen for its metabolism and most oxygen is freed into the tissues. The absence of nucleus, ribosomes, and mitochondria partly contributes to the red blood cell’s disc-like structure which leaves room for hundreds of millions of hemoglobin molecules found within the cells. Hemoglobin is a red and iron-rich protein that merges with oxygen to carry oxygen from the lungs to the body tissues. Both
Red blood cell and consequently cannot divide and have limited repair capabilities. The inability to carry out protein synthesis means that no virus can evolve to target mammalian red blood cells. However, infection with parvoviruses (such as human parvovirus B19) can affect erythroid precursors, as recognized by the presence of giant pronormoblasts with viral particles and inclusion bodies, thus temporarily depleting the blood of reticulocytes and causing anemia. Human red blood cells are produced through a process named erythropoiesis, developing from committed stem cells to mature red blood cells in about 7 days. When matured, in a healthy individual these cells live in