Final answer:
The central cavity of hemoglobin and oxygen binding sites are different; the binding sites are where oxygen molecules attach to the iron atoms in hemoglobin, while the central cavity has other roles in the molecule's structure and function.
Step-by-step explanation:
The central cavity of hemoglobin is different from the oxygen binding sites. Hemoglobin consists of four subunits, each containing an iron atom, which serves as the oxygen binding site where oxygen molecules are transported.
The central cavity does not bind oxygen but may have structural or allosteric functions in hemoglobin. The phenomenon known as cooperativity, where the binding of one oxygen molecule affects the affinity for oxygen of other binding sites on the same hemoglobin molecule, is key for its function.
Moreover, hemoglobin will only transport oxygen if the iron is in the Fe²⁺ state, as the oxidation to Fe³⁺ prevents oxygen transport.