Quizz

 In a cell permeable only to K+, the resting membrane potential would be called the___________________ potential for K+, which is ___________ mV.

resting membrane, -90

In an excitable cell, also permeable to Na+ and Cl-, the electrochemical gradient for Na+ causes it to move___________ the cell.

into

Excitable cells, like neurons, are more permeable to ___________ than to ___________.a.What acts as a chemical force that pushes K+out of the cell? ___________________b.What force tends to pull K+back into the cell? _________________________

K+, Na+, a. concentration gradient. b. electrical gradient

Because the neuron is permeable to Na+as well as K+, the resting membrane potential is not equal to the equilibrium potential for K+; instead, it is ___________ mV.

-90

What compensates for the movement (leakage)of Na+and K+ions? _________________________

Na+/P+ pump

What will happen to the resting membrane potential of an excitable cell if: (Write pos or neg to indicate which way the membrane potential would change.)
a.extracellular fluid concentration of K+ (goes up)___________
b. ̄extracellular fluid concentration of K+ (goes down)___________
c.extracellular fluid concentration of Na+ (goes up)___________
d. ̄number of passive Na+channels (goes down) ___________
e.open voltage-gated K+channels ___________
f.open voltage-gated Na+channels___________

less negative
more negative
less negative
less negative
more negative
less