Cell Membranes and Neurophysiology 1

Question 1

Ratio of K+, Na+, Cl-, HCO3- (Extracellular: Intracellular)

Answer 1

1:35; 10:1, 5:1; 2:1

Question 2

Pump/Leak Model Concept

Answer 2

Both Active pumps and leaky channels work simultaneously in the same membrane but are INDEPENDENT of each other.

Question 3

Active pumps move from what concentrations?

Answer 3

low to high

Question 4

Channels move from what concentrations?

Answer 4

high to low

Question 5

What pump requires ATP and what pump doesn’t?

Answer 5

Active pumps DO (Na+K+ATPase)

Channels do NOT (go through concentration gradient)

Question 6

Chemical force is also known as

Answer 6

concentration force

Question 7

What is the resting membrane potential for a K+ leaky channel? Na+ leaky channel?

Answer 7

-100; +65

Question 8

What is resting membrane potential also called?

Answer 8

Electrochemical equilibrium

Question 9

Electrochemical equilibrium potential for a single highly permeant ion species is controlled by what?

Answer 9

concentration gradient

Question 10

Electrochemical equilibrium occurs when

Answer 10

the chemical forces and electrical forces are equal and opposite

Question 11

Cell membrane potential is controlled by (2)

Answer 11

degree of ion permeability and ion concentrations

Question 12

What is the resting membrane potential of a neuron? Why is this?

Answer 12

~ -90mV; because the Na+ channel is NOT very leaky and does not move ions around easily

Question 13

Changes in any ion channel’s permeability or ion concentration gradient will ___ the membrane potential.

Answer 13

MODIFY