Lecture 7: Resting Membrane Potential

Question 1

When measuring membrane potential the convention is

Answer 1

inside with respect to outside

Question 2

Cells maintain gradients of ions by means of

Answer 2

primary active transport

Question 3

It requires what to separate charges?

Answer 3

Energy

Question 4

Charges move through ______ and are separated by _____

Answer 4

Conductors and insulators

Question 5

Define electrochemical gradient

Answer 5

A Combination of an Electrical gradient and a chemical gradient

Question 6

Ions subjected to an electrochemical gradient will

Answer 6

move

Question 7

The Membrane potential of a cell is due to what

Answer 7

the electrical gradient across a cell membrane due to the unequal distribution of charges (ions)

Question 8

Membrane is measured in what unnits

Answer 8

Millivolts or mV

Question 9

True or False; Membrane potential is static

Answer 9

false; not constant

Question 10

The resting membrane potential (RMP) is a

Answer 10

special case of steady-state balance between active transport and leakage of ions

Question 11

True or false; A steady state is not an equilibrium

Answer 11

true

Question 12

For most cells the RMP is typically between what

Answer 12

-20 mV and -90mV

Question 13

Define Depolarizing, repolarizing, hyperpolarization

Answer 13

Depolarizing = membrane potential moving towards 0
Repolarization = membrane potential becoming more negative to initial stage
Hyperpolarization = making a membrane potential more negative past initial stage

Question 14

The amount of voltage necessary to keep the molecule inside the cell is called the

Answer 14

equilibrium potential

Question 15

Define equilibrium potential

Answer 15

The membrane potential that exactly opposes the steady state electrochemical gradient for an ion

Question 16

When calculating the equilibrium potential we calculate it at what temperature

Answer 16

37 degrees Celsius

Question 17

We use the what equation to calculate equilibrium potential and what is it

Answer 17

Nernst Equation

Eion = 61/z X log (ION out/ ION in)

Question 18

Is the equilibrium potentials positive or negative for the following ions
K+
Na+
Ca2+
Cl-

Answer 18

K+ = negative
Na+ = positive
Ca2+ = positive
Cl- = negative

Question 19

The equilibrium potential for each ion is ______________ of the concentration of the other ions

Answer 19

independent

Question 20

What is the relative number of leakage channels (Relative permeability) of;
K+
Na+
Ca2+
Cl-

Answer 20

K+ = 50
Na+ = 1
Ca2+ = 0
Cl- = 10

Question 21

When predicting the RMP we use what equation

Answer 21

Goldman

Question 22

The Goldman equation is basically what

Answer 22

3 nrest equations put together

Question 23

Write the Goldman Equation for Na+, K+ and Cl-

Answer 23

RMP = 61 log ((((P of k (K+ out) + P of Na (Na+) out + P of Cl (Cl-) IN ///////// P of K (K+) in + P of Na (NA+) in + P of Cl (Cl-) OUT )))

Question 24

What is the RMP for a normal healthy person

Answer 24

-78

Question 25

What is the RMP for a person with kidney failure caused by what

Answer 25

-67

caused by elevated K+ out

Question 26

What is the RMP for sever diarrhea and what caused it

Answer 26

-89

Decreased K+ out

Question 27

K+ typically moves ____ of the cell when it opens, where the other salts typically more ____

Answer 27

out; in

Question 28

To understand why ions move the way they do we need to consider both ______ and ______

Answer 28

Equilibrium potential

Membrane potential of the cell

Question 29

When ion channels open the ion always moves to make what = what

Answer 29

membrane potential = equilibrium potential