Lecture 2: Resting Neuronal Membrane Potential

Question 1

What do neurons have across their membrane?

Answer 1

a potential difference

Question 2

What does a change in membrane potential result in?

Answer 2

information and can generate action potentials

Question 3

What leads to the development of a concentration gradient?

Answer 3

an uneven distribution of ions and electric charge

Question 4

What is the movement of charge called?

Answer 4

current (I) which is measured in amps

Question 5

What is current dependent upon?

Answer 5

the potential difference (the difference in charge between the positive and negative poles) measured in volts
the ability of charge to move in a particular substance

Question 6

What allows for capacitance in a plasma membrane?

Answer 6

ions can interact across the neuronal membrane

Question 7

What is the role of ion transporters?

Answer 7

actively move ions against concentration gradients and create ion concentration gradients e.g. maintaining a high concentration of Na+ ions outside the cell and a high concentration of K+ ions inside the cell

Question 8

What are the two main types of ion transporter?

Answer 8

Na+/K+ pump and Ca2+ pump (ATPase pumps)

Question 9

How do ion exchangers work?

Answer 9

powered by ions moving down their concentration gradient which allows them to move ions against their concentration gradient

Question 10

What does the ion concentration gradient represent?

Answer 10

potential - this forms the basis for neuronal signalling

Question 11

What are the different ways in which an ion channel can be gated?

Answer 11

voltage-gated, ligand-gated and mechanically-gated

Question 12

What allows for selectivity in ion channels?

Answer 12

the presence of a selectivity filter which is consisted of eight oxygen atoms arranged in a manner which allows for the corresponding ion to be energetically relaxed

Question 13

What is equilibrium in regards to concentration / electrical gradients?

Answer 13

equilibrium is the point at which the concentration and electrical gradients balance, such that there is no NET movement of an ion

Question 14

What generates the resting membrane potential?

Answer 14

selective K+ permeability

Question 15

In which electrochemical gradients is considerable potential stored within neurons?

Answer 15

electrochemical gradients of Na+ and Ca2+ across the membrane