Synapses Cambridge Biology

What's the difference between ligand-gated channel proteins and voltage-gated channel proteins?

The neuromuscular junction is one which connects A and B. What are A and B?

With reference to an "action potential" describe which is the synaptic knob or presynaptic neurone and the postsynaptic neurone.

What is a neurotransmitter? Give an example.

What is the role of Calcium ions in cholinergenic synapses?

What's the role of SNARE proteins?

After a neurotransmitter successfully allows the electrical impulse to pass from one neurone to another, what happens to the neurotransmitter? Use the example of ACh.

Some snake venoms are neurotoxins. They can cause muscle paralysis. How can this occur?

Answer explanation

Toxin binds to receptor sites on the post-synaptic membrane and stops ACh from binding. This doesn't generate an action potential because the ligand-gated sodium channels remain closed.

Alternatively, toxin may stimulate ACh receptors, cause sodium channels to open and cause continuous depolarisation and action potentials.

Toxin may stop or reduce ACh from being recycled or may inhibit acetylcholinesterase.

What are 2 roles of synapses?

What does this phrase mean: "Exocytosis of a neurotransmitter"?