The Martian Rover has just discovered a life form (code-named Ralph) on Mars. You have been asked to help with the analysis of Ralph's nerve-like cells carried out at 10º C at which the Nernst constant equals 55 mV. You are given the following data for Ralph's nerve-like cells which contain no other charged particles in significant concentrations. Show all calculations
Out In P
Na+ 10 100 1
Li+ 100 1 .01
Rb+ 15 15 1
Cl- 50 1 0.1
Fl- 1 100 1
Pr- 50 5 1
Br- ? ? 0
a.) What must be the Br- concentrations in and out? Why?
b.) Calculate Ralph's membrane potential? Why did you chose that method??
c.) Given your calculation in b above, could any charged particle be in equilibrium across the membrane? Why?
d.) Suppose PCl goes to 1000. What happens to membrane potential? Why did you make that assumption to calculate? Could you make another assumption? What do you now calculate?? Did you get the same answer?? Why or why not?
e.) What should [Cl] inside approximately equal at 3 msec after this change in PCl? Why?