How does the structure and composition of the erythrocyte ensure its function?

The erythrocyte is shaped like a biconcave disc, which allows it to capture more oxygen molecules from the blood by increasing its area. This form provides easy and unobstructed passage of the erythrocyte through the blood vessels. It is noteworthy that a mature erythrocyte does not have a nucleus, otherwise its movement and transport of oxygen would be impossible. The erythrocyte contains hemoglobin – a protein that can easily capture oxygen and carbon dioxide and give them away just as easily. Thus, erythrocytes are involved in gas exchange.