The chloride shift

• carbon dioxide main carried as HCO ions in plasma but some carried in red blood cells or by simple solution
• carbon dioxide respiration diffuses into RBC - reacts with water to form carbonic acid which dissociates into hydrogen ions and HCO3 ions via carbonic anyhydrase catalyst
• HCO3 ions dissolve out of red blood cells and chlorine ions diffuse in to balance the charge - chloride shift