Mammalian RBC are biconcave, circular, non nucleated. The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule, that can bind oxygen and is responsible for the red color of the cells. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological cell function, such as deformability and stability, while traversing the circulatory system and specifically the capillary network. In humans, mature red blood cells are flexible and oval biconcave disks. They lack a cell nucleus and most organelles, in order to accommodate maximum space for hemoglobin.

──────────────────────────────────────────────────────────────────────────────────────────