So if we examine the PKA value of the side chain groups in Aspartate and Glutamate, the PKA value is 4.1. And what that means is, below 4.1, these groups are very likely to be protonated. But above 4.1, these groups are very likely to be deprotonated. And so at a physiological PH of around seven, these two groups will exist in their deprotonated state. And these two groups are known as the carboxylate ion groups. And so they will bear a full negative charge.