Every molecule in your body has a story to tell. This tale is about hemoglobin, the class of oxygen-binding molecules that make oxygen transport in complex creatures such as us possible. Hemoglobins are proteins that contain the heme moiety, a planar molecule binding iron (Fe) and maintaining it in the +2 oxidataion state (denoted Fe(II)).
Hemoglogins in the Animal Kingdom
Hemoglobins in almost all vertebrates is a heterotetramer (that is, four (‘tetra’) individual of different (‘hetero’) proteins) composed of two α-globin and two β-globin polypeptides (a fancy word for proteins). The heme part is bound in a pocket formed by structure of each globin unit. The movement and interactions between the subunits increases hemoglobin’s ability to bind oxygen.