The amount of oxygen unloaded from hemoglobin at the tissue level increases when A) PCO₂ in the tissue increases. B) the concentration of DPG in the red blood cells increases. C) the concentration of DPG in the red blood cells decreases. D) both (a) and (b) above. E) both (a) and (c) above.

Question

Quizplus · Accepted Answer

Increased PCO2 in the tissue results in an increase in H+ concentration, which lowers the pH. Lowered pH and increased DPG concentration both shift the oxygen dissociation curve to the right, meaning that hemoglobin is less able to hold onto oxygen and more is released to the tissue.

The Amount of Oxygen Unloaded from Hemoglobin at the Tissue