The Integumentary, Skeletal and Muscular Systems
At the neuromuscular junction of a skeletal muscle, neurotransmitters must contact receptors on the muscle fiber sarcolemma to transmit the signal for muscle contraction. That neurotransmitter must subsequently be enzymatically broken down, so that it is removed from the receptor, “resetting it” to receive another message. Mancy “chemical weapons” are in fact inhibitors of the enzyme necessary to break down the neurotransmitter in question, causing it to remain attached to the receptor indefinitely.
The enzyme inhibited by most chemical weapons is probably:
It is expected that you are aware that the neurotransmitter acetylcholine is virtually the only important one that acts at the neuromuscular junctions of skeletal muscles. Acetylcholinesterase is the enzyme that normally degrades it, and if this is inhibited, paralysis will occur. Choice B is incorrect as it refers to the neurotransmitter itself (but might trick you if you weren’t careful). Choices C and D are unsupported by the passage.