Around a quarter of the human body cells are red blood cells, or erythrocytes. These RBCs are developed in the bone marrow produced at approximately 2.4 million red blood cells per second.  Erythrocytes circulate in the body for 100 to 120 days. It is the same reason why we can only donate blood once every 3 to 4 months. Men have an average of 5.2 million RBCs per cubic millimeter meanwhile 4.6 million in women. If you are a regular blood donor, you’ll notice that there are more men who passed the blood donation screening than women. The iron-rich protein known as hemoglobin is the main component of the red blood cells. It is responsible for the red color as iron binds with oxygen. Each hemoglobin molecule has four iron atoms and each of which binds to 1 oxygen molecule with 2 oxygen atoms. Around 33% of an erythrocyte is hemoglobin normally 15.5 g/dL in men and 14 g/dL in women. Red blood cells play an important role in transporting oxygen-rich blood from the lungs to the tissues and cells. RBCs have cell membranes composed of lipids and proteins essential for physiological function while working within the capillary network through the circulatory system.  In addition, red blood cells aid in the removal of carbon dioxide. They contain the carbonic anhydrase enzyme which allows for a reaction of water and carbon dioxide to form carbonic acid and separate hydrogen and bicarbonate ions. Hydrogen ions bind with hemoglobin while bicarbonate ions go to the plasma removing approximately 70% of carbon dioxide. Twenty percent of carbon dioxide binds with hemoglobin which then released in the lungs. Meanwhile, the remaining 7% gets dissolved in the plasma.

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Write a summary of the previous text in Vietnamese:
Hiểu kiến thức cơ bản về tế bào hồng cầu. Hiểu về cơ chế hoạt động của hemoglobin trong máu. Hiểu về vai trò của tế bào hồng cầu.