Inhibition of protein synthesis in translocation steps occurs by
**Core Concept**
Protein synthesis is a complex process involving transcription, translation, and translocation. Translocation is the step where the ribosome moves along the mRNA, bringing the growing polypeptide chain through the protein-conducting channel of the ribosome. Inhibition of protein synthesis at this step can occur through various mechanisms.
**Why the Correct Answer is Right**
The correct mechanism of inhibition of protein synthesis in translocation steps is through the action of antibiotics such as Chloramphenicol. Chloramphenicol binds to the 50S ribosomal subunit, specifically to the peptidyl transferase center, which is involved in peptide bond formation. This binding inhibits the translocation of the ribosome along the mRNA, preventing the growing polypeptide chain from passing through the protein-conducting channel. As a result, protein synthesis is inhibited.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the inhibition of protein synthesis in translocation steps.
* **Option B:** This option is incorrect because it does not specifically relate to the mechanism of inhibition of protein synthesis in translocation.
* **Option D:** This option is incorrect because it is not a known mechanism of inhibition of protein synthesis in translocation steps.
**Clinical Pearl / High-Yield Fact**
Chloramphenicol is a broad-spectrum antibiotic that inhibits protein synthesis by binding to the 50S ribosomal subunit. It is effective against a wide range of bacteria, including those that cause respiratory and gastrointestinal infections.
**Correct Answer:** C. Chloramphenicol