Question

The following diagram summarizes the carbonic acid-bicarbonate ion buffer system of the blood.

CO2 + H2O H2CO3 HCO3 + H+
Which of the following equations show the reaction that takes place when there are very little protons ( H+) in the blood?
A. H2CO3 → CO2 + H2O

B. CO2 + H2O → H2CO3

C. HCO3 + H+ → H2CO3

D. H2CO3 → HCO3 + H+

Answer 1

When there are few protons in the blood, the carbonic acid-bicarbonate buffer system favors the conversion of carbonic acid to carbon dioxide and water, as represented by equation A. H2CO3 → CO2 + H2O.

Step-by-step explanation:

The correct equation that shows the reaction taking place in the blood when there are very few protons (H+) present is A. H2CO3 → CO2 + H2O. This is because when there is a low concentration of protons in the blood, indicating that the blood is more alkaline, the reaction shifts to produce more carbon dioxide (CO2) and water (H2O), thus reducing the levels of carbonic acid (H2CO3) and restoring balance to the buffer system. The reaction moves in the opposite direction when there is an excess of hydrogen ions, forming more carbonic acid through the bicarbonate ion buffer system (HCO3- + H+ → H2CO3).