Answer to Question 1
ANS: B
G6PD is an enzyme in the hexose monophosphate pathway and is important to maintain reduced glutathione in the red cell. This substance (reduced glutathione) is critical for preventing oxidative damage to red cell proteins. This pathway does not produce any energy and has no function in carbon dioxide transport. Its deficiency is very common worldwide, affecting millions of people; in fact, it is the most common human enzyme deficiency in the world.
Answer to Question 2
ANS: D
Integral proteins include the glycophorins, which give the red cell its overall negative charge and are also responsible for the blood group antigens including those of the ABO and Rh systems. The peripheral proteins form the skeletal network of the red cell membrane.