In: Biology
Which of the following events occur during the initiation of translation in prokaryotic cells? (more than one answer will apply)
Select one or more:
a. The small ribosomal 30S subunit will bind the the Shine Dalgarno sequence in the mRNA.
b. tRNA carrying fMet will bind to the AUG start codon.
c. The large ribosomal 50S subunit will form a sandwich with the mRNA in between the two subunits
d. tRNAs will bring amino acids to the A site of the ribosome.
e. The ribosome will make peptide bonds between amino acids
Which of the following events occur during the initiation of translation in prokaryotic cells?
Options A & B are correct.
a. The small ribosomal 30S subunit will bind the Shine Dalgarno sequence in the mRNA.
30S ribosome with the help of IF-3 does bind the Shine-Dalgarno sequence on the mRNA, 8 bases upstream of the START codon AUG.
b. tRNA carrying fMet will bind to the AUG start codon.
With the help of IF-2-GTP, fMet-tRNA is recruited to the AUG codon to initiate translation.
c. The large ribosomal 50S subunit will form a sandwich with the mRNA in between the two subunits.
mRNA is NOT sandwiched between 50S and 30S subunits. It is bound by 30S subunit only. 50S subunit accommodate tRNAs which interact via its anticodon with codon present in the mRNA.
d. tRNAs will bring amino acids to the A site of the ribosome.
This is the step in elongation (not initiation) of translation.
e. The ribosome will make peptide bonds between amino acids
Peptide bond formation is also step in elongation (not initiation) of translation.