On average what is the life duration of the red blood cells? Where are they destroyed? What is the destination of the heme groups after the destruction of hemoglobin molecules?
On average red blood cells live around 120 days. The spleen is the major organ where old red blood cells are destroyed.
During the red blood cell destruction the heme groups turn into bilirubin and this substance is then captured by the liver and later excreted in the bowels as part of the bile.