Final answer:
Nerve gases, including sarin, target and inhibit acetylcholinesterase, which leads to an accumulation of acetylcholine and persistent nerve impulses, causing uncontrolled muscle contractions and potential fatal paralysis.
Step-by-step explanation:
Nerve gases, such as sarin, exert their effects by inhibiting the enzyme acetylcholinesterase (AChE). These substances are classified as acetylcholinesterase inhibitors. When acetylcholinesterase is inhibited, acetylcholine, a neurotransmitter essential for nerve impulse transmission, builds up in the synaptic cleft. This ongoing presence of acetylcholine results in continuous nerve impulse transmission and uncontrolled muscle contractions. In the case of nerve agent exposure, this can lead to a state where muscle paralysis and respiratory failure occur, which can be fatal without immediate treatment.
Substances that inhibit acetylcholinesterase, like sarin, soman, and certain insecticides or drugs used for treating Alzheimer's and myasthenia gravis, work by binding to the enzyme and preventing it from breaking down acetylcholine. This disruption in nerve transmission can result in a range of effects, from muscle twitching to severe convulsions and ultimately death if not promptly treated with antidotes such as atropine, which is an anticholinergic drug.