Hemoglobin is a protein in red blood cells that transports oxygen from the lungs to tissues throughout the body. It binds to oxygen and other gases through chemical bonding. This transport of oxygen via hemoglobin is an example of how chemical bonding enables important biological functions in the human body. Blood doping artificially enhances the oxygen-carrying capacity of blood by increasing the red blood cell count or hemoglobin concentration, and has been used by some athletes to improve endurance performance despite its health risks.
![What Is Hemoglobin ? ,[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)