Malathion is a commonly used pesticide that inhibits acetylc

Malathion is a commonly used pesticide that inhibits acetylcholinesterase, the enzyme that breaks down the neurotransmitter acetylcholine. In 1-2 sentences, explain what would happen in the post synaptic cell of an insect exposed to this toxin.

Solution

Malathion is an organophosphate compound which contains the active cholinesterase inhibiting metabolite, Malaoxon. Malaoxon is an inhibitor of acetylcholinesterase, which under normal conditions hydrolyses acetylcholine into acetic acid and choline. However,as malaoxon inhibits acetylcholinesterase the peak concentration of acetylcholine increase at the synaptic cleft resulting in over stimulation of the cholinergic neuron instead of it returning to its resting state (induced by the hyrdolysis of acetylcholine) post activation. This results in muscle spasms, which eventually lead to death of the insect.