Membrane Potential I

Question 1

What will happen if the membrane is permeable to only one ion and impermeable to the counterion?

Answer 1

an electrical charge is established

Question 1

How much is one mole?

Answer 1

6.02x10^23

Question 2

An imbalance in the number of cations and anions inside a cell produces the ____.

Answer 2

membrane potential

Question 2

What does z stand for in the Nernst Equation?

Answer 2

valence of the ion in question

Question 2

If an ion is at equal concentrations across a membrane, what will be its equilibrium potential?

Answer 2

zero

Question 3

The ion concentration difference and the electrical potential difference across the membrane govern ______.

Answer 3

passive movement of an ion across the membrane

Question 5

If the membrane is ______ to both Na+ and Cl-, nothing will happen and the cell will survive.

Answer 5

impermeable

Question 5

What does T stand for in the Nernst Equation?

Answer 5

temperature

Question 6

The passive movement of an ion across the membrane is governed by two forces: _____ and _____.

Answer 6

its concentration difference; the electrical potential difference across the membrane

Question 7

What does R stand for in the Nernst Equation?

Answer 7

the gas constant

Question 9

____ charge is much stronger than ____ charge.

Answer 9

Electrical; osmotic

Question 11

How do animal cells solve the problem of controlling their volume?

Answer 11

by surrounding themselves with an external solution that also contains nonpermeating molecules

Question 12

What if Vm is not the same as ECl?

Answer 12

either a) the membrane is impermeable to the ion or b) the ion must be pumped across the membrane

Question 14

If the membrane is impermeable to both Na+ and Cl-, _____ and the cell _____.

Answer 14

nothing will happen; will survive

Question 15

The electrochemical gradient is made by?

Answer 15

The ion concentration difference and the electrical potential difference across the membrane in a cell

Question 16

If the membrane is permeable to both Na+ and Cl-, they both will ______ and the cell will ______.

Answer 16

diffuse into the cell; burst

Question 17

A beaker of H2O will osmotically support a column of 1.0M glucose _____ high.

Answer 17

900 feet

Question 17

What does E stand for in the Nernst Equation?

Answer 17

equilibrium potential in millivolts

Question 18

E = (RT/zF) lne (Co/Ci)

Answer 18

the Nernst Equation

Question 19

What does F stand for in the Nernst Equation?

Answer 19

the Faraday constant

Question 21

Bulk solutions are always electrically _____.

Answer 21

neutral

Question 22

What does Co stand for in the Nernst Equation?

Answer 22

outside concentration of the ion

Question 22

What is the equilibrium potential?

Answer 22

electrical potential difference across the membrane that must exist if the ion is to be at equilibrium

Question 24

What does Ci stand for in the Nernst Equation?

Answer 24

inside concentration of the ion

Question 25

the Nernst Equation

Answer 25

E = (RT/zF) lne (Co/Ci),

Question 26

If the membrane is ______ to both Na+ and Cl-, they both will diffuse into the cell and the cell will burst.

Answer 26

permeable

Question 27

What if Vm is the same as ECl?

Answer 27

no pump is needed to maintain the equilibrium

Question 28

Membrane potentials are produced by?

Answer 28

an imbalance in the number of cations and anions inside a cell

Question 29

The ion concentration difference and the electrical potential difference across the membrane combined make \_\_\_\_\_\_.

Answer 29

the electrochemical gradient

Question 30

How do cells maintain ionic equilibrium?

Answer 30

for every charged ion that enters the cell, one of the same charge is pushed out of the cell because like repels like