Biochemistry 4th Edition by Christopher Mathews,Kensal van Holde, Dean Appling, Spencer Anthony Cahill

Exercise 3

Measurements of oxygen binding by whole human blood, at 37 °C, at pH 7.4, and in the presence of 40 mm Hg of CO₂ and normal physiological levels of BPG (5 mmol/L of cells), give the following: (a) From these data, construct a binding curve, and estimate the percent oxygen saturation of blood at (1) 100 mm Hg, the approximate partial pressure of O₂ in the lungs, and (2) 30 mm Hg, the approximate partial pressure of O₂ in venous blood.
(b) Under these conditions, what percentage of the oxygen bound in the lungs is delivered to the tissues
(c) Using the data in Figure 7.16 (page 253), repeat the calculation of part (b) if the pH drops to 6.8 in capillaries but goes back to 7.4 as CO₂ is unloaded in the lungs.