And what that tells us is our cells and the outside portion of cells, even though it does consist of water, it cannot be pure water because pure water isn't a good system because it can prevent these drastic changes in PH from actually taking place. So the curve shows that adding acid to pure water creates an immediate and drastic change in PH. And if the cells of our body and the blood and the various biological systems in our body consisted of pure water and nothing else, then any acid based reaction that took place inside our body would change the PH abruptly destroying the many different types of biological molecules by disrupting their molecular structure. As can be seen from the following curve. Because this drop in our PH means a very, very large change in PH takes place for a very small amount of H plus ions that have been added to our mixture. So what the cell does is or what our body does is for example, this is true for our blood, for our cells and other parts of our body.