Resting Membrane Potential

Question 1

Cells of the body have

Answer 1

electrical properties. These properties are evident at the cell membrane, a boundary that prevents the free movement of ions into and out of the cell.

Question 2

in part, the flow of ions through these channels is due to their

Answer 2

differences in concentration across the membrane.

Question 3

The flow of ions through these channels can also be influenced by

Answer 3

their electrical charges, because of the attraction between opposite charges.

Question 4

There are two basic types of ion channels:

Answer 4

leak channels and (2) gated channels

Question 5

Leak channels are always

Answer 5

open

Question 6

because of the cell membrane’s hydrophobic interior,

Answer 6

ions cross it through ion channels

Question 7

thus, ions can “leak”

Answer 7

across the membrane, down their concentration gradient.

Question 8

Gated channels are

Answer 8

closed until opened by specific signals.

Question 9

Chemically gated channels are

Answer 9

opened by specific chemicals;

Question 10

voltage-gated channels

Answer 10

are opened by a change in the electrical property of the cell membrane.

Question 11

when we consider the “sides” of the cell membrane, the inside of most cell membranes is

Answer 11

negatively charged

Question 12

outside of the cell membrane,

Answer 12

positively charged

Question 13

This uneven charge distribution across the cell membrane means that the membrane

Answer 13

polarized

Question 14

small voltage difference, called

Answer 14

potential, can be measured across the cell membrane.

Question 15

In an unstimulated (or resting) cell, we refer to this

Answer 15

as the resting membrane potential.

Question 16

The resting membrane potential is generated primarily by the uneven distribution of

Answer 16

K+, Na+, and negatively charged proteins across the cell membrane.

Question 17

The resting membrane potential results from

Answer 17

differences in the concentrations of ions across the membrane and the permeability characteristics of the membrane.

Question 18

Cl− concentrations are higher

Answer 18

outside the cell.

Question 19

Cl− movement across the membrane is

Answer 19

limited

Question 20

Given that the membrane is relatively permeable

Answer 20

Cl−