1. Oxygen transport: Oxygen combines with hemoglobin in red blood cells to form oxyhemoglobin. Oxyhemoglobin reaches different parts of the body. Oxyhemoglobin breaks down in body cells and oxygen and hemoglobin are released. As a result, body cells get the necessary oxygen.
Hb4 + 4O2 → 4Hbo2
Actually hemoglobin reacts with 4 oxygen molecules to form Hb4o8.
Hb4 + O2 → Hb4o2
Hb4o2 + O2 → Hb4o4
Hb4o4 + O2 → Hb4o6
Hb4o6 + O2 → Hb4o8
This reaction is extremely fast and takes less than 0.01 second. Temperature, pH and red blood cell diphosphoglycerate affect this reaction.
2. Transport of carbon dioxide: Carbon dioxide reacts with hemoglobin in body cells to form carbaminohemoglobin compound. Carbaminohemoglobin comes from the compound body cells to the walls of the alveoli. The compound breaks down in the walls of the alveoli and turns into carbon dioxide and hemoglobin. Carbon dioxide is then released from the body.
CO2 + HbNH2 → HbNHCOOH
Hemoglobin acts as the sole carrier for transporting oxygen and carbon dioxide in the human body. That is, oxygen and carbon dioxide transport is not possible without red blood cells.