Question

During initiation of translation in prokaryotes, ________. Select one: a. the large subunit is the first part of the ribosome to associate with the mRNA b. the initiator Met-tRNA.met binds to the A site of a ribosome c. the ribosomal small subunit binds to the 5' cap and then scans for the first AUG d. both 70S and 30S ribosome subunits must simultaneously recognize an mRNA to bind e. a sequence in the rRNA base pairs with a sequence in the mRNA to position a ribosome at the start codon

Answer 1

Answer:

The correct answer is option e. "a sequence in the rRNA base pairs with a sequence in the mRNA to position a ribosome at the start codon".

Explanation:

During initiation of translation in prokaryotes, a sequence in the rRNA base pairs with a sequence in the mRNA to position a ribosome at the start codon. The sequence of the mRNA that base pairs with the sequence in the rRNA is called The Shine-Dalgarno sequence and is located at -7 to -4 of the translational start codon. The Shine-Dalgarno sequence is as follows "AGGAGG" and its complementary to part of the 3′ end of 16S rRNA. Once mRNA binds to the small subunit of the ribosome at the P site, translation initiates and the A site of the ribosome is opened.