TRANSPORT OF CO2

What percentage of CO₂ is dissolved in blood plasma

during transport from respiring tissues to the lungs?

• 10%

• 30%

• 60%

• 90%

Which form of CO₂ transport involves binding

to the amino group of haemoglobin?

• Dissolved in plasma

• As bicarbonate ion

• As carbaminohaemoglobin

• As carbonic acid

3. What is the main enzyme that catalyzes the formation of

4. carbonic acid (H₂CO₃) from CO₂ and H₂O in red blood cells?

• Hemoglobin

• Carbonic anhydrase

• Chloride ion

• Oxygenase

What is the purpose of the chloride shift during CO₂ transport?

• To increase the oxygen-carrying capacity of blood

• To maintain electrochemical charge/balance in red blood cells

• To dissolve more CO₂ in blood plasma

• To form carbaminohaemoglobin

At the lungs, what happens to the bicarbonate ion (HCO₃-)?

• It remains in the plasma

• It binds to oxygen

• It diffuses back into the red blood cell

• It is converted to carbaminohaemoglobin

What percentage of CO₂ is transported as bicarbonate ion (HCO₃-)?

• 10%

• 30%

• 60%

• 90%

Which of the following occurs in the red blood cell to prevent a decrease in pH during CO₂ transport?

• Formation of carbaminohaemoglobin

• Dissociation of H₂CO₃ into CO₂ and H₂O

• Binding of H+ with haemoglobin to form hemoglobinic acid (HHb)

• Diffusion of CO₂ into blood plasma

What is the reverse process that occurs at the lungs regarding bicarbonate ion (HCO₃-)?

• • Formation of carbaminohaemoglobin

• • HCO₃- diffuses into the plasma

• • HCO₃- combines with H+ to form H₂CO₃

• Dissociation of CO₂ and H₂O

During exhalation, CO₂ is finally expelled from the body after diffusing into which area?

• Blood plasma

• Red blood cells

• 
  Alveolar space

• Interstitial fluid

Which of the following is true about the transport of CO₂ in the blood?

• 90% is dissolved in plasma.

• All CO₂ is transported as carbaminohaemoglobin.

• Haemoglobin acts as a buffer during CO₂ transport.

• Carbonic anhydrase is found in blood plasma only.