Neuronal signalling

Question 1

What type of signalling is neuronal signalling an example of?

Answer 1

Paracrine signaling

Question 2

how many subunits does a nicotinic receptor have?

Answer 2

five (pentameric receptor)

Question 3

When acetylcholine binds to a nicotinic receptor in a postsynaptic cell, what happens to allow the signal to be transduced?

Answer 3

Conformational change opens the channel allowing a rapid influx of Na+ ions. This depolarises the membrane.

Question 4

What is the function of the T-Tubule in the post-synaptic muscle cell?

Answer 4

T-Tubule allows the current on the membrane to enter the cell.

Question 5

Once the membrane potential has decreased significantly, what type of receptor is activated on the sarcoplasmic reticulum membrane?

Answer 5

Ryanodine receptor

Question 6

What does activation of the receptors on the SR cause to happen?

Answer 6

release of calcium in to the cytosol

Question 7

How does an increase in intracellular calcium concentration lead to muscle contraction in a muscle cell?

Answer 7

Calcium binds to troponin protein and causes a conformational change.
This moves tropomyosin and causes the myosin head to come in contact with the underlying actin.