Hemoglobin - 10 million X

This model of hemoglobin is 10 million times real life. Hemoglobin is responsible for carrying and delivering the oxygen in our blood. In humans, hemoglobin contains 4 subunits consisting of two alpha and two beta subunits non-covalently bound. Each subunit contains a heme group with an iron (Fe) ion capable of binding an oxygen molecule (O2). This model shows hemoglobin in a deoxygenated state with one alpha and one beta subunit in red and their corresponding hemes in pink; the second pair of alpha and beta subunits are shown in the reverse colors.