CO2 Concentration

• What does CO2 concentration affect?

  oxygen unloading
• When does Hb give up its oxygen more readily?

  At a higher partial pressure of carbon dioxide
• What happens when cells respire?

  They produce carbon dioxide which raises the pCO2 
• What does the raised pCO2  increase?

  The rate of oxygen unloading (ie the rate at which oxyhaemoglobin dissociates to form haemoglobin and oxygen)- so the dissociation curve shifts right

  The saturation of blood with oxygen is lower for a given pO2 , meaning that more Oxygen is being released

  This is called the BOHR EFFECT
• how does increasing co2 conc increase the dissociation of oxygen?

  Decreasing pH of blood/ increases acidicty
• Describe a Bohr Shift?

  The greater concentration of CO2, the more readily Hb releases its O2 because the more CO2 there is, the lower the pH, the greater the Hb shape change, the more readily O2 is unloaded, the more O2 available for respiration