Which subunit is the small ribosomal subunit in prokaryotes?

Which subunit is the small ribosomal subunit in prokaryotes?

• A. 30S
• B. 40S
• C. 60S
• D. 50S

Answer: (A)

In bacteria, ribosomes are built from two subunits: a smaller decoding subunit and a larger catalytic subunit. The smaller subunit is the decoding unit that binds mRNA and reads codons, matching them with tRNA anticodons to ensure correct amino acid incorporation. The larger subunit provides the peptidyl transferase activity needed to form peptide bonds. So the small ribosomal subunit in prokaryotes is the decoding unit—the part that handles mRNA decoding when the ribosome assembles with the large subunit.

In bacteria, ribosomes are built from two subunits: a smaller decoding subunit and a larger catalytic subunit. The smaller subunit is the decoding unit that binds mRNA and reads codons, matching them with tRNA anticodons to ensure correct amino acid incorporation. The larger subunit provides the peptidyl transferase activity needed to form peptide bonds. So the small ribosomal subunit in prokaryotes is the decoding unit—the part that handles mRNA decoding when the ribosome assembles with the large subunit.