Question

question 83
which of the following events in translation is the first to occur in eukaryotes?

○ elongation of the polypeptide

○ base pairing of activated methionine-trna to aug of the messenger rna

○ binding of the larger ribosomal subunit to smaller ribosomal subunits

○ the small subunit of the ribosome recognizing and attaching to the 5 cap of mrna

Explanation:

To determine the first event in eukaryotic translation, we analyze each option:

• Elongation occurs after initiation, so it's not first.
• Base pairing of methionine - tRNA to AUG happens after the small ribosomal subunit attaches to mRNA.
• Binding of large ribosomal subunit to small occurs after the small subunit has attached to mRNA and the initiator tRNA has bound.
• The small ribosomal subunit first recognizes and attaches to the 5' cap of mRNA, which is the initial step of translation initiation in eukaryotes.

Answer:

D. the small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA