Question

Which of the following are responsible for a rightward shift in the oxygen-hemoglobin dissociation curve?

• A. Lower \(PO_{2}\)
• B. Higher \(H_{+}\)
• C. Higher \(pCO_{2}\)
• D. Both (b) and (c)

Hint:

Remember the Bohr effect: increased H\textsuperscript{+} and CO\textsubscript{2} reduce hemoglobin's oxygen affinity, shifting the curve right and enhancing oxygen delivery to tissues.

Answer 1

The Correct Option is D

A rightward shift in the oxygen-hemoglobin dissociation curve indicates decreased hemoglobin affinity for oxygen, facilitating oxygen release to tissues. This shift is caused by factors such as increased hydrogen ion concentration (higher \(H^{+}\), causing lower pH) and increased partial pressure of carbon dioxide (higher \(pCO_{2}\)), both of which occur during increased metabolic activity. Lower \(PO_{2}\) does not cause this shift but reflects oxygen availability.

Therefore, both (b) higher \(H^{+}\) and (c) higher \(pCO_{2}\) cause a rightward shift.