Anatomy and physiology

Question

Explain in the bicarbonate buffer system what happens to hydrogen ion concentration when CO2 levels are increased.  Assume not other causative events.  You must defend in detail your answer.  You must also put this into your own words and include any references that you consulted in your investigations.  You must also put your answer into your own words in a way that you understand. And the term for the middle compound would be ?

Answer 1

First, it's important to acknowledge what the purpose of the bicarbonate buffer system is - it's a mechanism to regulate pH in the blood. When CO2 enters red blood cells or blood plasma it reacts with water to form carbonic acid in the following reaction CO2 + H2O -> H2CO3. Carbonic acid will then break down into the bicarbonate ion (HCO3-) and a hydrogen ion (H+). More CO2 will drive the reactions above, resulting in more HCO3- and H+.

Remember that pH is essentially a measure of how much H+ is in a solution - more H+ means more acidic/ lower pH. The reaction creating carbonic acid and hydrogen ions is reversible, so it can be adjusted to bring pH into homeostasis as needed. Bicarbonate ions can bind with H+ if we need to raise pH/make blood more alkaline which is why HCO3- is said to act as the buffer in this system.

Good luck with your homework assignment and be sure to cite Geoff ;)