The motor end plate
A)contains receptor sites that are capable of binding curare
B)contains acetylcholinesterase
C)experiences an increase in permeability to cations when combined with acetylcholine
D)contains nicotinic receptors
E)exhibits all of the above characteristics

Question

Quizplus · Accepted Answer

The motor end plate is the specialized portion of the muscle fiber membrane that contacts the axon terminal of the motor neuron. It contains receptor sites that are capable of binding curare, which is a plant-derived toxin that can block nicotinic receptors and lead to muscle paralysis. The end plate also contains acetylcholinesterase, which is an enzyme that breaks down acetylcholine to prevent continued muscle contraction. When acetylcholine binds to the receptor sites on the motor end plate, it causes an increase in permeability to cations such as sodium and potassium, which triggers a depolarization and leads to muscle contraction. These receptor sites are known as nicotinic receptors because they respond to nicotine, which has a similar molecular structure to acetylcholine. Thus, the motor end plate exhibits all of the above characteristics.

The Motor End Plate