Pest Control Technician Practice Exam

How do organophosphates affect cholinesterase activity?

1. They stimulate increased activity

2. They have no impact on activity

3. They enhance enzyme production

4. They inhibit cholinesterase activity

The correct answer is: They inhibit cholinesterase activity

Organophosphates are a class of chemicals commonly used in pesticides, and their mechanism of action is closely related to the inhibition of cholinesterase activity. Cholinesterase is an essential enzyme that breaks down the neurotransmitter acetylcholine in the synapses of the nervous system. When organophosphates enter the body, they bind to the active site of cholinesterase, preventing it from performing its normal function. This inhibition leads to the accumulation of acetylcholine, which can cause overstimulation of cholinergic receptors. As a result, the nervous system becomes hyperactive, leading to a variety of symptoms such as muscle twitching, respiratory distress, and potential fatality if exposure is sufficiently high. Understanding this mechanism is crucial for pest control technicians as it underscores the importance of handling organophosphate products with care to avoid adverse health effects. While other options might suggest different interactions with cholinesterase, none accurately reflect the true biochemical effect of organophosphates, which is their potent inhibitory action on this critical enzyme.