Okay, so at a PH of two, what is the net charge on this protein? So, let's begin with this group and basically go one by one all the way to the 7th group, this alpha carboxyl group. So at the alpha amino group, we're a PH of two. And since two is below 8.0, that means this will have a positive charge. So once again, remember that what the PKA value tells us is so if the PH is equal to the PKA, that is when our H atom will be lost or gained. And in this particular case, at a PH of eight or higher, this is when the H atom on this nitrogen will be lost.