Final answer:
The complete hemoglobin molecule consists of heme groups, polypeptide chains (globins), and iron ions. It features two alpha and two beta globin chains, each with a heme group that contains an iron ion, essential for oxygen transport.
Step-by-step explanation:
The complete hemoglobin molecule is composed of both heme groups and polypeptide chains (globins), accompanied by iron ions. Specifically, hemoglobin contains four globin subunits, two designated as alpha chains and two as beta chains, each bound to a heme group. The heme group, in turn, contains an iron ion which plays a crucial role in oxygen binding and release.
Each alpha chain consists of 141 amino acids, and each beta chain has 146 amino acids, which are arranged into a specific sequence to form the unique quaternary structure of the protein. The iron within the heme interacts with the surrounding environment to facilitate the oxygen binding process. Altogether, there are four heme groups and iron ions in one hemoglobin molecule.