Final answer:
Acetylcholinesterase (AChE) breaks down acetylcholine in the synaptic cleft, with the primary role of ensuring that the neurotransmitter does not cause prolonged muscle contractions and allows the synapse to reset for further signal transmission.Thus the correct option is b.
Step-by-step explanation:
Acetylcholinesterase (AChE) plays a crucial role in the synaptic cleft by breaking down the neurotransmitter acetylcholine (ACh) after it has been used to transmit a nerve impulse. ACh is responsible for stimulating muscle contraction and is degraded by AChE into acetyl and choline; this process allows the neuromuscular junction to be ready for the next nerve impulse. Inhibiting AChE could lead to prolonged muscle contractions, which is undesirable.
The function of acetylcholinesterase on the target cell is: b) Breaks down acetylcholine. By breaking down ACh, AChE ensures that the neurotransmitter does not overstimulate the muscle fibers, which would otherwise result in extended and unwanted muscle contractions. This action is crucial for the regulation of muscle movement and for the ability of the synapse to efficiently transmit subsequent signals.