Q32 / 200 · MHT CET - Medical 2026 (24 April Shift 1) · Biology
The oxyhaemoglobin dissociation curve shifts towards left due to increase in ___________.
- Correct answerApH
- Btemperature
- CDPG
- D$\text{ppCO}_2$
Solution
The oxyhaemoglobin dissociation curve shifts to the left when the affinity of haemoglobin for oxygen increases.
This left shift occurs under conditions such as low $pCO_2$, low $H^+$ concentration (which corresponds to high pH), low temperature, and low 2,3-DPG levels.
An increase in pH means a decrease in $H^+$ concentration, which favours the formation of oxyhaemoglobin and shifts the curve to the left.
Conversely, an increase in temperature, $pCO_2$, or DPG decreases the affinity of haemoglobin for oxygen and shifts the curve to the right.
Answer: pH
This left shift occurs under conditions such as low $pCO_2$, low $H^+$ concentration (which corresponds to high pH), low temperature, and low 2,3-DPG levels.
An increase in pH means a decrease in $H^+$ concentration, which favours the formation of oxyhaemoglobin and shifts the curve to the left.
Conversely, an increase in temperature, $pCO_2$, or DPG decreases the affinity of haemoglobin for oxygen and shifts the curve to the right.
Answer: pH
Hence, the correct answer is option: 'A'.