Exam 2: Ch 5 Nernst and Goldman

Question 1

Nernst equation states that the equilibrium potential depends on

Answer 1

absolute temp (K)

charge on permeant ion

ratio of the ionic concentration on the two sides of the membrane

Question 2

nernst equation

Answer 2

Esubx = RT/zF ln (X1/X2)

Question 3

reduced Nernst equation at 18 celcius

Answer 3

Esubx = .058/z log (X1/X2)

Question 4

diffusion of a single ion species down its concentration gradient unaccompanied by its counterion can set up…

Answer 4

an electric potential difference between the two sides of the semipermable membrane

at equilibrium, the emf across the membrane is equal to the equilibrium potential

Question 5

membrane potential equation

Answer 5

Vm = Vin - Vout

Question 6

is extracellular/intracellular ion [ ]s on top or bottom of nernst?

Answer 6

extracellular in numerator

intracellular in denominator

Question 7

what is the Goldman equation used for

Answer 7

calculating the steady-state potential for multiple ions

Question 8

nernst equation gives the equilibrium potential for one ion, but in reality the plasma membrane is permeable to several…

Answer 8

ionic species at a time, which may be asymmetrically distributed

Question 9

dynamic steady state

Answer 9

in biological systems where exchanges of matter and energy occur continuously across a system