We're only increasing, we're only focusing on the PH effect, increasing the H plus ion. So why is it that when we increase the H plus ions in the red blood cells and in our blood system, why is it that the curve shifts to the right? How do these H plus ions actually affect that hemoglobin molecule? Well, it turns out that in the hemoglobin molecule, we have several groups that can actually bind H plus ion. So one of the group is basically the terminal residue, the amino group on the terminal residue of the alpha subunits. And the other group are the histidine residues found on the beta 146 position and the alpha 122 position.