Now, since proteins consist of different combinations of these readily ionizable amino acids, what that means is they will have different net charge values at some specific PH value. For example, they will have different net charges at the physiological PH of around seven. Now, what it also means is that every protein will have a unique PH value at which the overall net charge on that protein, on that polypeptide, will be zero. And this will be the case. At a specific PH value, all the charges on all our amino acids on that protein will exactly cancel one another out. The net charge will be zero.