Which process is inhibited by the action of erythromycin at the ribosomal level?

• A. Transcription
• B. Translation
• C. Replication
• D. Splicing

Answer: (B)

Erythromycin is an antibiotic that specifically targets the ribosome, which is essential for the process of translation in protein synthesis. It binds to the 50S subunit of the bacterial ribosome, inhibiting the translocation step during protein synthesis. This action effectively prevents the ribosome from moving along the mRNA strand, thereby stalling the production of proteins. Translation requires the ribosome to assemble amino acids into polypeptide chains based on the sequence of codons in the mRNA. By inhibiting this process, erythromycin effectively limits bacterial growth and function.

In contrast, transcription refers to the synthesis of RNA from a DNA template and occurs in the nucleus (in eukaryotes) or the cytoplasm (in prokaryotes) but is not affected by erythromycin. Replication involves the copying of an organism’s DNA prior to cell division and also operates independently of ribosomal activity. Splicing is the process by which introns are removed from pre-mRNA to produce mature mRNA and occurs after transcription but is likewise not influenced by erythromycin.