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Sequence of Ribosome Assembly

APBIO-NNGYZY

A scientist uses the process of cell fractionation to isolate and collect in a test tube a sample of ribosomes from a eukaryotic cell.

The scientist adds mRNA transcripts to the test tube along with all tRNA molecules and amino acids needed for protein synthesis, with the exception of the amino acid methionine and its associated tRNA molecule.

After allowing the sample to sit for several minutes, which of the following would the scientist expect to find in the test tube?

A

Small ribosomal subunits associated with mRNA transcripts.

B

Small ribosomal subunits associated with an mRNA transcript and an initiator tRNA molecule bound to the start codon on the mRNA transcript.

C

Small ribosomal subunits associated with an mRNA transcript, with initiator tRNA molecules bound to the start codon on the mRNA transcripts resting in the P-site of the large ribosomal subunits.

D

Free floating polypeptide chains, mRNA transcripts, small ribosomal subunits and large ribosomal subunits.