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. What our body does is it uses instead of using pure water, it uses water and a mixture of a buffer system. Now, what exactly is a buffer system? Well, a buffer system is a solution in which we have water as a solvent, but we also have a certain concentration of an acid and an equal concentration of the conjugate base to that particular acid.