Studying Cell Biology
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B.3. RBC Ion Transport <<Previous Problem Next Problem>> PPrint PDF
 

 

Typically, the cytoplasm of most animal cells is rich in potassium and poor in sodium, a condition opposite to that found in the blood and extracellular fluids surrounding these cells.  Examine closely the following set of data, obtained by precise analysis of the ionic composition of blood from 3 mammalian species.

Ionic Composition (mM)
Intracellular
Extracellular
Species   Na+ K+ Cl-   Na+ K+ Cl-
Human   19 136 78   119 5.0 113
Dog   135 10 87   152 5.1 112
Cat   142 8 84   157 5.3 112

 

A)   (6 pts) Assuming these data are valid, what mechanism(s) could be proposed to account for the non-equilibrium condition that apparently exists between a human erythrocyte and its environment, with respect to these ions?
 
 
 
 
B)   (8 pts) How can the interspecific differences be explained?  (Note:  your reasoning must be explicit!)
 
 
 
 
C)   (6 pts) Discuss succinctly experimental procedures for testing your hypothesis(es) and the expected results.
 

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