* Next, the four plates are carefully fitted into the hemoglobin molecule in such a way that oxygen molecules can get to the iron ions but water molecules cannot get to them.
हीमोग्लोबिन में पाया जानेवाला आयरन खुद - ब - खुद ऑक्सीजन से नहीं जुड़ता या छुटता ।