Re: Ph of water-heads -- lots of water tested

Good post but let's add a bit more info...

In our bodies we have several buffer systems. In the blood the principle buffer is bicarbonate:

H2CO3 <----> HCO3- + H+ <----> H2O + CO2

This system, composed of two weak acids, resists change even more than the HA <--> H+ + A- system described in the previous post. This is the principle buffer in our blood and is very important in many biochemical and phsyiological functions, eg exhaling carbon dioxide or in renal physiology. Carbonic anhydrase is an important enzyme involved in this reaction in the cell.

Intracellular buffer is principally phosphate and proteins. The phosphate buffer is a more complex buffer system than the carbonate buffer system.

Phosphate buffer system:

H3PO4 <---> H2PO4- + H+ <---> HPO4(-2) <---> H+ + PO4 (-3)

As protons are added the reaction proceeds to consume the protons and produce the weak bases. Proteins inside the cell also have many functional groups which can associate with protons.

Bottom line is that all these buffer system act in concert, as well as organ function, to maintain the body at a constant pH. Maintaining a constant pH is essential for many (most) enzymes in our bodies to function correctly. These chemical systems as well as respiratory physiology and renal physiology ensures that our internal environment does not vary. You cannot change by eating certain foods...it just doesn't work that way.

In plain water the pH changes dramatically with the addition of a strong acid or base since the only products formed are protons (H+) or hydroxide ions (OH-). When these same acids or bases are added to a system containing a buffer the pH only changes slightly since most (many) of the free protons are used up in forming the conjugate acids or bases respectively. Measure your blood pH rather than urine or saliva and you will find that no matter what you eat your blood (and thus your internal pH) remains constant.

Wonder what happened to the post I made about renal phsyiology...I thought this site was for educating?

regards...