• Changes in the oxygen dissociation curve?as a result of carbon dioxide levels?are known as the?Bohr effect, or?Bohr shift
• When the?partial pressure?of carbon dioxide in the blood is high, haemoglobin’s affinity for oxygen is reduced
  • This is the case in?respiring tissues, where cells are producing carbon dioxide as a waste product of respiration
  • This occurs because?CO₂?lowers the pH of the blood
    • CO_2?combines with water to form carbonic acid
    • Carbonic acid dissociates into hydrogen carbonate ions and hydrogen ions
    • Hydrogen ions bind to haemoglobon, causing the release of oxygen
• This is a helpful change because it means that?haemoglobin gives up its oxygen more readily?in the respiring tissues where it is needed
• On a graph showing the dissociation curve, the curve?shifts to the right?when CO₂?levels increase
  • This means that?at?any given partial pressure of oxygen, the percentage saturation of haemoglobin is lower at higher levels of CO₂

The dissociation curve shifts to the right as a result of the Bohr effect. This means that any given partial pressure of oxygen, the percentage saturation of haemoglobin is lower at higher CO₂levels.