transporting carbon dioxide

• Chloride Shift

  For every hydrogen carbonate ion that diffuses out of the red blood cell, a chlorine ion with the same charge diffuses into it.

  1. Carbon dioxide reacts with water to form HCO
  2. HCO splits up into H and HCO
  3. HCO diffuses out of the red blood cell
  4. Cl diffuses into the red blood cell

  Now, the carbon dioxide produced in tissues eventually needs to be removed from our bodies when we exhale.

  For this to happen, when the red blood cells reach the lungs, the reverse reactions take place.
• Chloride Shift 2

  First off, the chloride shift takes place in the opposite direction.

  So, Cl- diffuses out of the red blood cell and HCO3- diffuses into the red blood cell.

  The H+ ions that remain in the red blood cell then react with HCO3-, producing H2CO3.

  Finally, H2CO3 splits up into H2O and CO2.

  This CO2 then diffuses down the concentration gradient to enter our lungs, where it’s exhaled out!

  To prevent the pH of the blood getting too low, H+ ions react with haemoglobin and HCO3-
• Hyperventilation

  When too much carbon dioxide is exhaled, the blood becomes less acidic and the oxyhaemoglobin dissociation curve shifts to the left. This means that haemoglobin binds with oxygen more readily and releases oxygen less readily. Therefore, tissues receive less oxygen for respiration, which can lead to symptoms including dizziness and fainting.