a. False The reverse is true; deoxygenated blood can carry more CO2 than oxygenated blood at a given carbon dioxide pressure.
b. True In the lungs the blood oxygen saturation rises shifting the curve from A to B and the CO2 content and pressure fall from point X to point Y.
c. False It would merely shift the position on a given dissociation curve.
d. False Plasma does not become saturated with CO2; CO2 content remains proportional to PCO2; the initial sharp rise is due to formation of carbamino compounds – this falls off sharply as the number of free amino groups declines.
e. False The amount of CO2 in solution is the same for both curves for any PCO2; differences in total CO2 content are due to differences in bicarbonate and carbamino content; at low oxygen pressures, the desaturated hemoglobin is increasingly more effective in buffering hydrogen ions and, by the law of mass action, favours formation of bicarbonate ions from carbon dioxide.