In the beginning of April, we will have an entire unit devoted to how pH is maintained in our bodies.  Can you believe it?  I think it will be Unit 23.  So, we'll only lightly cover this issue now.

    CO₂ is a gas that we mainly think of as a waste gas.   I mean, we know that we need to breathe in oxygen and breath out CO₂.   But we actually use the CO₂ in our bodies to help us maintain our blood pH.  Certainly, we do not want an excess of CO₂ in our blood, so we still have to get rid of it.  But at least we have a use for it if it has to be in our blood anyway.

    You see, CO₂ gas undergoes a chemical reaction in our blood.  It gets changed into a buffer.  Buffers are molecules that regulate pH to a certain level.  The buffer that CO₂ becomes is called bicarbonate, but we'll go into detail on that later.  What you should know is that this particular buffer tends to regulate any solution to take on a pH of approximately 7.4.  That is the pH of the blood.  And that pH works well as the blood interacts with the other fluid environments of the body (extracellular solutions and intracellular solutions).

    OK?

© 2006 STCC Foundation Press
written by Dawn A. Tamarkin, Ph.D.