What is hemoylobin?

Hemoglobin is an iron-containing protein found in red blood cells that transports oxygen from the lungs to the rest of the body and removes carbon dioxide. It consists of four polypeptide chains, each folded into a globin domain, which are arranged in a tetrahedral shape. Each globin domain is composed of eight alpha helices, seven of which form a hydrophobic core, while the eighth is involved in oxygen binding. The iron atom is bound to a porphyrin ring located in the center of the globin domain. Oxygen molecules bind to the iron atom in a cooperative manner, meaning that the binding of one oxygen molecule increases the affinity of the other three binding sites for oxygen. This cooperativity is essential for the efficient transport of oxygen in the body.