Source: Heme molecule image, Public Domain, http://en.wikipedia.org/w/index.php?title=File:Heme_b.svg&page=1 Heme; Public domain: http://en.wikipedia.org/wiki/File:Heme_b.svg
A quaternary pigment protein found on red blood cells, hemoglobin is primarily used to transport oxygen and some carbon dioxide throughout the blood.
The term used to describe when oxygen is bound to hemoglobin; oxygen + hemoglobin = oxyhemoglobin.
A term used to describe the protein structure of hemoglobin.
This is the iron group in the center of each globular protein in a hemoglobin molecule; therefore one hemoglobin molecule has four heme groups associated to it. The heme group is what oxygen binds to when red blood cells are circulating oxygen throughout the body.
The actual iron atom within the heme group to which oxygen binds.