Chapter 13, Problem 86E

The binding of oxygen by hemoglobin (Hb), giving oxy-hemoglobin (HbO₂), is partially regulated by the concentration of H₃O+ and dissolved CO₂ in the blood. Although the equilibrium is complicated, it can be summarized as

${\text{HbO}}_2\left(aq\right)+{\text{H}}_3{\text{O}}^{+}\left(aq\right)+{\text{CO}}_2\left(g\right)\rightleftharpoons {\text{CO}}_2-\text{Hb}-{\text{H}}^{+}+{\text{O}}_2\left(g\right)+{\text{H}}_2\text{O}\left(l\right)$

(a) Write the equilibrium constant expression for this reaction.

(b) Explain why the production of lactic acid and CO₂ in a muscle during exertion stimulates release of O₂ from the oxy-hemoglobin in the blood passing through the muscle.