Ion Channels And Ionotropic Receptors

Question 1

How does our phospholipid bilayer acts as a capacitor & resistor?

Answer 1

It prevents ions from crossing and thus separates the charges. It resists the flow of ions across the membrane

Question 2

What is the role of ion channels?

Answer 2

Reduce resistance of phospholipid bilayers allowing ions to cross the membrane

Question 3

How is membrane potential generated?

Answer 3

From uneven distribution of ions particularly K+, Na+ and Cl-

Question 4

What and where are the important ions to create resting potential?

Answer 4

Na+ higher outside cell
Ca++ higher outside cell
Cl- Higher outside cell
K+ higher inside cell

Question 5

What are the properties of Ion Channels?

Answer 5

1) Selectivity (Na+/ K+/ Cl-)
2) Gating properties (Type of control)
3) Is transmembrane with water-filled pores
4) Rate and direction of ion movement is dependent on concentration gradient

Question 6

What are the different gatings of ion channels?

Answer 6

1) Passive (Leaky K+ Channels)
2) Voltage gated (Electrical impulse simulated)
3) Mechanically gated
4) Ligand gated (Eg. Nicotinic acetylcholine receptors/ GABA)