Ery­thro­cytes

Red blood cells. They con­sist of 30 per­cent hemo­glo­bin, a lar­ge pro­te­in mole­cu­le that sur­rounds the red blood pig­ment respon­si­ble for oxy­gen trans­port. Like all blood cells, the ery­thro­cytes are for­med in the bone mar­row of the hip bones and long tubu­lar bones.