So when the tissue is exercising, it produces more CO2 molecules, which ultimately ends up with produces more H plus ions. And because we have a higher concentration of H plus ions, that will make our blood plasma more acidic, thereby lowering the PH of the blood plasma. And this effect is known as the Bore Effect. So it basically affects our hemoglobin's ability to bind to oxygen. The next question is how exactly does the presence of carbon dioxide and H plus ions affect hemoglobin's ability to bind to oxygen? Well, basically, hemoglobin has a special site we call the allosteric site.