Question

check all of the statements that are true about bacterial ribosomes.

check all that apply

peptide bond formation is catalyzed by a protein.
peptide bond formation is catalyzed by an rna.
the small subunit aligns the start codon with the a site.
uncharged trnas exit through the e site.
ribosomes cannot load onto an mrna until transcription is complete.

Explanation:

Evaluate peptide bond catalysis

$$ \text{Peptidyl transferase activity is catalyzed by the 23S rRNA (a ribozyme), not a protein.} $$

Evaluate start codon alignment

$$ \text{During initiation, the small subunit aligns the start codon (AUG) with the P site, not the A site.} $$

Evaluate tRNA exit and transcription coupling

$$
LATEXBLOCK0
$$

Answer:

• Peptide bond formation is catalyzed by a protein.
• Peptide bond formation is catalyzed by an RNA. (Correct answer)
• The small subunit aligns the start codon with the A site.
• Uncharged tRNAs exit through the E site. (Correct answer)
• Ribosomes cannot load onto an mRNA until transcription is complete.