To carry outMETABOLISM , oxygen is taken up by hemoglobin

Chapter 13, Problem 122P

(choose chapter or problem)

To carry out metabolism, oxygen is taken up by hemoglobin (Hb) to form oxyhemoglobin \(\left(\mathrm{HbO}_{2}\right)\) according to the simplified equation

\(Hb(aq)+O_{2}(aq)\xrightarrow{{k}}HbO_{2}(aq)\)

where the second-order rate constant is \(2.1 \times 10^{5} / M \cdot s\) at \(37^{\circ} \mathrm{C}\). (The reaction is first order in Hb and \(\mathrm{O}_{2}\).) For an average adult, the concentrations of Hb and \(\mathrm{O}_{2}\) in the blood at the lungs are \(8.0 \times 10^{-6}\ M\) and \(1.5 \times 10^{-6}\ \mathrm{M}\), respectively. (a) Calculate the rate of formation of \(\mathrm{HbO}_{2}\). (b) Calculate the rate of consumption of \(\mathrm{O}_{2}\). (c) The rate of formation of \(\mathrm{HbO}_{2}\) increases to \(1.4 \times 10^{-4}\ \mathrm{M} / \mathrm{s}\) during exercise to meet the demand of increased metabolism rate. Assuming the Hb concentration to remain the same, what must be the oxygen concentration to sustain this rate of \(\mathrm{HbO}_{2}\) formation?