Resting Cell Membrane

Question 1

At equilibrium of an ion, which gradients balance?

Answer 1

Electrical

Chemical

Question 2

What does the Nernst equation allow us to work out?

Answer 2

The equilibrium potential for a particular ion

Question 3

State the Nernst equation for Ek

Answer 3

Ek = (61/z) x log10([K+]o/[K+]i)

z = charge of ion
Remember it is always the extracellular concentration over the intracellular concentration

Question 4

Which channels would we open to cause hyperpolarisation?

Answer 4

K+ or Cl-

Question 5

Which channels would we open to cause depolarisation?

Answer 5

Na+ or Ca2+

Question 6

What are the 3 types of gating?

Answer 6

Ligand
Voltage
Mechanical

Question 7

How does fast synaptic transmission occur?

Answer 7

The receptor protein has an intrinsic ion channel.

Question 8

What happens at excitatory synapses?

Answer 8

Membrane depolarisation due to channels opening for Na+ or Ca2+
Excitatory post-synaptic potential stimulated

Question 9

Which molecules are excitatory?

Answer 9

Acetylcholine

Glutamate

Question 10

What happens at inhibitory synapses?

Answer 10

Hyperpolarisation due to opening of K+ or Cl- channels

Inhibitory post-synaptic potential generated

Question 11

Which molecules are inhibitory?

Answer 11

Glycine

GABA (an amino acid)

Question 12

Why does slow synaptic transmission occur?

Answer 12

The receptors and the channel are separate proteins

Question 13

What are the 2 types of slow synaptic transmission?

Answer 13

Direct G-protein gating

Via an intracellular messenger

Question 14

Which other anions have an effect on potential?

Answer 14

Phosphate
Bicarbonate
Amino acids
Charged groups on proteins