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. And these H plus ions and CO2 ions can actually bind to the allosteric site found on hemoglobin. And once they bind, they create a conformational change, a change in the three dimensional structure of hemoglobin. And what this does is it decreases the ability of hemoglobin to actually bind to oxygen.