Ribozyme is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 23S rRNA
A ribozyme is an RNA molecule that works as an enzyme (a catalyst). During translation, the ribosome joins amino acids by peptide bonds. The ribosome itself acts as the catalyst for this step. In bacteria, the catalytic part is the 23S rRNA of the large subunit, so 23S rRNA is the enzyme, the ribozyme.
(1) 28S rRNA — Incorrect. 28S rRNA is found in the large ribosomal subunit of eukaryotes, not bacteria. It is not the ribozyme named for peptide bond formation.
(2) 23S rRNA — Correct. It catalyses the formation of the peptide bond in bacteria.
(3) 18S rRNA — Incorrect. 18S rRNA is part of the small subunit of the eukaryotic ribosome. It does not form peptide bonds.
(4) 5.8S rRNA — Incorrect. 5.8S rRNA is a small structural rRNA of the eukaryotic large subunit. It is not the ribozyme.
NCERT Extract:
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