Question

Compare and contrast how oxygen and carbon dioxide are transported in the bloodstream, and the properties of each molecule that determine its necessary mode of transport. How do the properties of these molecules and their transporters determine where and how each gas enters or leaves the blood?

Answer 1

Transport of Oxygen in blood is as follows

• Minor portion is dissolved in blood plasma
• Majority is carried by hemoglobin

Transport of Carbondioxide in blood is as follows

• Minor portion is dissolved in plasma
• Binds to hemoglobin
• Majority is carried as a bicarbonate buffer.

It must be noted that the majority of the oxygen is transported as oxyhemoglobin while carbon dioxide is transported as bicarbonate ions. It is the partial pressure of oxygen molecule that determines its binding factor with hemoglobin. Most of the oxygen binding to hemoglobin happens at tissue cappillaries.When pH of blood decreases then oxygen dissociation from hemoglobin is found to increase.Increas in partial pressure of carbondioxide will decrease hemoglobin affinity towards carbon dioxide.