**Core Concept**
Neutrophil extracellular traps (NETs) are networks of extracellular fibers, mainly composed of chromatin, that are generated by neutrophils to trap and kill pathogens. The lysis of chromatin is a critical step in the formation of NETs, and certain amino acids play a role in this process.
**Why the Correct Answer is Right**
The amino acid histidine is crucial in the lysis of chromatin during NET formation. Histidine is a precursor to histamine, which is involved in the regulation of chromatin decondensation and the subsequent release of DNA. Histidine also acts as a cofactor for the enzyme histone H1 kinase, which is responsible for the phosphorylation of histone H1 and the subsequent disruption of chromatin structure. This allows for the release of chromatin from the nucleus, which is then extruded out of the cell to form NETs.
**Why Each Wrong Option is Incorrect**
**Option A:** Asparagine is not directly involved in the lysis of chromatin during NET formation.
**Option B:** Glutamine is an important amino acid for cellular metabolism, but it is not specifically involved in the lysis of chromatin during NET formation.
**Option C:** Cysteine is an essential amino acid for the synthesis of glutathione, a key antioxidant in neutrophils, but it is not directly involved in the lysis of chromatin during NET formation.
**Clinical Pearl / High-Yield Fact**
The formation of NETs is an important mechanism by which neutrophils contribute to the innate immune response, and the lysis of chromatin is a critical step in this process. Histidine, through its role in histamine regulation and histone H1 kinase activity, plays a key role in this process.
**Correct Answer:** C. Histidine.
Free Medical MCQs Β· NEET PG Β· USMLE Β· AIIMS
Access thousands of free MCQs, ebooks and daily exams.
By signing in you agree to our Privacy Policy.