Dichloro-diphenyl-trichloroethane (DDT) is one of the most widely used insecticide. Which of the following statement is NOT true about DDT?
**Core Concept**
DDT is a persistent organochlorine insecticide that acts on the nervous system of insects by disrupting normal neurotransmitter function. Its mechanism of action involves the inhibition of an enzyme called acetylcholinesterase, leading to an accumulation of acetylcholine in the synaptic cleft and causing overstimulation of the nervous system.
**Why the Correct Answer is Right**
DDT acts as a competitive inhibitor of the enzyme cytochrome P450, specifically the isoenzyme CYP6, but not on acetylcholinesterase. This inhibition leads to the accumulation of toxic compounds in the insect's body, ultimately causing its death. The mechanism of action of DDT is distinct from other insecticides that target acetylcholinesterase.
**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because DDT is indeed a broad-spectrum insecticide that affects a wide range of insect species.
* **Option B:** Incorrect because DDT is a lipophilic compound that accumulates in the fatty tissues of animals, leading to bioaccumulation and biomagnification in the food chain.
* **Option C:** Incorrect because DDT has been shown to have a high degree of persistence in the environment, with a half-life of several years.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the use of DDT has been banned in many countries due to its potential environmental and health risks, including its association with various cancers and neurological disorders.
**Correct Answer: B. DDT is a broad-spectrum insecticide that affects a wide range of insect species.**