Carbon dioxide affects O₂ binding to Hb by: A) Hb competing with carbonic anhydride for CO₂. B) directly binding to heme-Fe in the oxygen binding site. C) forming iron carbonate with the heme-iron. D) forming H⁺ + HCO₃− where the H⁺ is an antagonist to oxygen binding to Hb. E) forming HCO₃− that combines with H⁺ to increase CO₂ binding.

Question

Quizplus · Accepted Answer

Carbon dioxide forms bicarbonate (HCO3-) and protons (H+) when it reacts with water, a reaction catalyzed by carbonic anhydrase. The protons (H+) can bind to hemoglobin, reducing its affinity for oxygen, which is known as the Bohr effect. This does not involve direct binding of CO2 to the heme iron or competing with oxygen at the binding site but affects oxygen binding indirectly through changes in the hemoglobin structure caused by proton binding.

Carbon Dioxide Affects O2 Binding to Hb By

Carbon Dioxide Affects O₂ Binding to Hb By