Question

Name three (3) characteristics of red blood cells which make them well suited to carry oxygen to tissues?

Answer 1

1) The RBCs are a anaerobic ie they don't need oxygen for their metabolism. Hence, they can carry oxygen without utilising it.

2) The RBCs have Hemoglobin which is an oxygen binding pigment. Hemoglobin exists in 4 forms. Without oxygen, the hemoglobin is in tight form. When one molecule of oxygen binds to the tight hemoglobin, it facilitates binding of other molecules also. And when the maximum 4 oxygen molecules are attached to the hemoglobin, it is said to be in a relaxed state. (This is called Cooperative binding). Hence, one molecule of hemoglobin can carries 4 molecules of oxygen. {Whereas myoglobin carries 1 molecule of oxygen at one time}

3) RBCs are biconcave in shape which increases their surface area. Greater surface area allows easy exchange of oxygen and carbon dioxide and rapid diffusion of other substances.

4) The RBCs are abundant in the blood (4.5-6.0 million cells/microlitre). Hence they can easily carry the oxygen to the tissues even when their concentration is less.