Textbook Problem 6.19

[Kaylee Messick 3J]

6.19) Hemoglobin (Hb) molecules in blood carry O2 molecules from the lungs, where the concentration of oxygen is high, to the tissues where it is low. In the tissues, the equilibrium H3O+ (aq) +HbO2- (aq) --> HHb (aq) + H2O (l) + O2 (aq) releases oxygen. When muscles work hard, they release lactic acid as a byproduct. a) What effect will the lactic acid have on the concentration of HbO2-?

I am a little confused on part A because I thought that lactic acid would produce more HHb, which would also cause the concentration of HbO2- to increase, however the textbook states that the concentration would actually decrease. I was wondering why it would decrease? Thanks!

[Carolina 3E]

The reason why HHb increases is because there is an increase of H3O+ from the lactic acid. The H3O+ from the lactic acid reacts with HbO2- to produce more HHb. So, an increase in reactants will cause the rxn to shift right and produce more products, therefore HbO2- (reactant) will decrease.