O2 and CO2 in the blood

Question 1

How is CO2 transported?

Answer 1

• 5% dissolved in plasma
• 10-20% as carbaminohaemoglobin. CO2 combines with NH2 groups in the polypeptide chains of Hb.
• 75-85% is converted into HCO3- in RBC cytoplasm.

Question 2

How does Hb act as a buffer?

Answer 2

• Binds with H+ ions in the cytoplasm to form haemoglobinic acid.