How many globin groups does each hemoglobin molecule have?

Each hemoglobin molecule is composed of four globin chains, which form a quaternary structure. Specifically, it consists of two alpha (α) and two beta (β) chains in adults, known as hemoglobin A (HbA). This structure allows hemoglobin to effectively bind and transport oxygen from the lungs to the tissues and facilitate the return transport of carbon dioxide from tissues back to the lungs. The presence of four globin chains is essential for the cooperative binding of oxygen, meaning that the binding of oxygen to one of the heme groups enhances the ability of the other heme groups in the same hemoglobin molecule to bind oxygen as well. Thus, understanding that hemoglobin contains four globin groups is crucial for comprehending its function in oxygen transport and the physiological processes involving red blood cells.