1) WHICH TYPE OF ION CHANENELS ARE FOUND ON THE NERVE CELL MEMBRANE?   

Voltage gated and ligand gated channels

2) name 3 differences between ligand gated and voltage gated ion channels?

Voltage-gated channels react and open when they are changes in the membrane potential whilst ligand gated open when a ligand binds to the channel

Secondly only voltage gated channels are responsible for the all-or-nothing phenomenon .

Lastly, voltage gated channels are usually Na+,Ca2+ or K+ channels whilst ligand gated channels have receptors such as Ach and GABA receptors

• 3.Compare ionotropic and metabotropic receptors.

Ionotropic receptors allow the binding of ionic ligands to them that opens up the ion channel, metabotropic receptors allow the binding of chemical ligands to the receptors, initiating a cascade of reactions via linking with a G protein

Only metabotropic receptors lead to the formation of a second messenger

Metabotropic receptors lead to metabolic changes whilst ionotropic receptors lead to opening of channels

The binging of a ligand to metabotropic receptor leads to longer effects as compared to the effects brought about by an ion binding to  an ionotropic receptor.

3.Classify the CNS receptor into ionotropic and metabotropic and know the transductions mechanism of each receptor.

Ionotropic : GABAA, Nicotinic receptors, Excitatory Amino Acid (EAA) and 5-HT3 receptors

Metabotropic receptors are divided into 2 groups

1. Adenylyl cyclase system with beta 1 and 2 , dopamine 1 ,dopamine 2 ,alpha 2, serotonin , muscarinic  2 ,serotonin A and B and GABA b  receptors

2.Phospholipase C system with alpha 1, serotonin 2 , muscarinic 1 and histamine 1.

4.Explain the difference between an EPSP and an IPSP and give examples of each

EPSP stands for excitatory post synaptic potential. It is an electrical charge that occurs within the post synaptic membrane of the neuron as a result of excitatory neurotransmitters. This can happen when, for example Glutamate binds to a Na+  Ca2+ channel.

IPSP stands for  inhibitory post-synaptic potential. It is an electrical charge that builds up in the post-synaptic membrane inhibiting the firing of an action potential. This happens when GABA binds to a chloride ion channel.

5.What is the role of calcium in the development of a synaptic potential?

 Calcium has the ability to directly depolarize the membrane, or it can act as a second messenger.On the axon terminals of neurons there are calcium channels. When an arrives, it stimulates calcium influx, which causes vesicles to leave the cell. Calcium is essential for the release of neurotransmitters.