And by forming this sold bridge, we essentially decrease the net charge in that localized region and that stabilizes the T state, the 10th state of that deoxy hemoglobin molecule. And what that does is it lowers definitive hemoglobin for oxygen and makes it more likely to unload that oxygen to the tissues of our body. And that means it shifts the entire curve to the right side. And that's precisely why when we go from no CO2 PH of 7.4 to no CO2 and a PH of 7.2 because we increase our h plus iron concentration, we essentially form these sold bridges. And that basically shifts the black curve to the blue position shown here. So once again, as the hydrogen ion concentration increases, the histidine side chain becomes protonated.