NEETZoologyBreathing and Exchange of Gases
When is dissociation of CO₂ from carbamino-haemoglobin likely to occur?
Options
- AWhen pCO₂ is high and pO₂ is low
- BWhen pCO₂ is low and pO₂ is high
- CWhen pCO₂ is high and pO₂ is high
- DWhen pCO₂ is low and pO₂ is low
Correct answer
B. When pCO₂ is low and pO₂ is high
Step-by-step solution
CO2 is carried by haemoglobin as carbamino-haemoglobin (about 20-25 per cent). This binding is related to the partial pressure of CO2. pO2 is a major factor which could affect this binding. When pCO2 is high and pO2 is low as in the tissues, more binding of carbon dioxide occurs whereas, when the pCO2 is low and pO2 is high as in the alveoli, dissociation of CO2 from carbamino-haemoglobin takes place, i.e., CO2 which is bound to haemoglobin from the tissues is delivered at the alveoli . RBCs contain a very high con