Question

Approximately what percentage of carbon dioxide is transported via the cardiovascular system via bicarbonate...

A. 10%

B. 20%

C. 30%

D. 40%

Answer 1

Approximately 85% of carbon dioxide is transported via the bicarbonate buffer system in the cardiovascular system. Carbon dioxide diffuses into red blood cells and is converted into bicarbonate ions and hydrogen ions. Bicarbonate ions are transported across the membrane into the plasma.

Step-by-step explanation:

The majority of carbon dioxide is transported via the cardiovascular system in the form of bicarbonate. Approximately 85% of carbon dioxide molecules are carried as part of the bicarbonate buffer system. This process involves carbon dioxide diffusing into red blood cells, where it is converted into carbonic acid by an enzyme called carbonic anhydrase.

The carbonic acid is then hydrolyzed into bicarbonate ions and hydrogen ions. Bicarbonate ions are transported across the membrane into the plasma, while hydrogen ions bind to hemoglobin.

Answer 2

Approximately 70% to 90% of carbon dioxide in the blood is transported via bicarbonate, with about 85% being the most representative figure, which exceeds the given options.

Step-by-step explanation:

The question pertains to the transportation of carbon dioxide (CO2) in the blood, specifically how much of it is transported via bicarbonate. The majority of CO2 is transported in the blood as bicarbonate. When CO2 diffuses into red blood cells, an enzyme called carbonic anhydrase catalyzes its conversion to carbonic acid (H2CO3). This acid then quickly dissociates into bicarbonate (HCO3-) and hydrogen ions (H+). This bicarbonate buffer system is responsible for transporting approximately 70% to 90% of CO2 in the blood. Specifically, about 85 percent of CO2 is carried in this manner to the lungs, where it can then be exhaled. In summary, the correct answer to the student’s question would be that approximately 90%, which is beyond any of the provided options, of CO2 is transported via bicarbonate in the cardiovascular system.