Exam 13: Translation of MRNA

The peptidyl transferase is a component of

During elongation, the polypeptide is removed from the tRNA in the P site and transferred to the amino acid in the A site.

What is the name of the enzyme that adds CCA to the 3' end of tRNAs?

What is responsible for binding the initiator tRNA in eukaryotes?

What site does the initiator tRNA bind to on the ribosome?

What site on the ribosome is primarily responsible for holding the growing polypeptide?

Suppose you performed a triplet binding assay with the triplet 5'-UAA-3'. What radiolabeled amino acids do you expect to find bound to the filter?

A tRNA's anticodon is 5'GGC3'. What amino acid is attached to it?

Transcription and translation may occur simultaneously in prokaryotic cells.

The decoding function is conducted by

Where does mRNA/tRNA codon-anticodon recognition take place?

The anticodon on the mRNA recognizes the codon on the tRNA.

The structure of the ribosome is uniform throughout a eukaryotic cell.

You are studying the DNA of a person who you know has two defective copies of the gene that encodes phenylalanine hydroxylase. You are surprised to find that this person also carries two defective copies of the gene for homogentisic acid oxidase. What disease symptoms will this person exhibit? (Assume pathway intermediates are not available from sources outside the phenylalanine breakdown pathway.)

All mature polypeptides contain a methionine at the N-terminus.

You perform a cell free translation experiment like Nirenberg and Matthaei, but you forget to write down what nucleotides you added to make the mRNA. You precipitate the translated polypeptides and measure the relative amount of radiolabeled amino acids incorporated into them. You get 25% proline, 25% threonine, 12.5% glutamine, 12.5% lysine, 12.5% asparagine, and 12.5% histidine. What nucleotides and in what % did you add to make the mRNA?

Kozak's rules for translation are similar to those for transcription in prokaryotes in that they both contain consensus sequences. In prokaryotes, the promoter consensus sequences are at -35 and -10. Where is the consensus sequence for translational initiation according to Kozak's rules?