Now, what about the alpha amino group? Well, the Alpha amino group contains a PKA of 8.0. And what that means is, because our normal physiological PH is seven, and because a PH of seven is below a PH of eight, what that means is every single one of our amino acids at the normal physiological PH will contain an alpha amino group that will predominate in this form because it is below a PH of eight. So if we put these two together, we see that because at the normal physiological PH, this will be negatively charged, and this will be positively charged, these two charges will essentially cancel out. And so the net charge on that amino acid at the normal physiological PH will depend on the charge that is found on that side chain group. And remember, a zwitter ion or a dipolar form of the amino acid basically means it will exist with this negative charge and this positive charge.