Studying
Cell Biology Preface | Introduction to Problem Solving | Problem Sets | Acknowledgments |
||||||||||
|
||||||||||
Hereditary spherocytosis (HS), a rare form of anemia in humans, is characterized by slightly spherical red blood cells. Affected individuals have fewer red cells than do normal individuals, possibly because HS cells are more susceptible to osmotic lysis than are normal cells (and because they are more readily trapped by the spleen): when placed in a slightly hypotonic saline solution that would cause little or no hemolysis in normal cells, significant numbers of HS cells burst, as illustrated in the following table:
To examine the mechanism responsible for HS, investigators suspended samples of normal and HS erythrocytes in identical physiological saline media and measured the uptake of radioactive sodium (22Na) over time. The data are presented in the figure below, as average fluxes +/- 1 S.E.
Consider this data, what you know about plasma membrane
structure and function, and answer the following questions. |
||||||||||