what iron containing protein transports oxygen
Hemoglobin (American) or haemoglobin (British) (/ËhiËmÉËÉ¡loÊbÉªn, ËhÉ-, -moÊ-/[1][2][3]); abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates[4] (with the exception of the fish family Channichthyidae[5]) as well as the tissues of some invertebrates.