Exam 22: Gene Expression: Iiprotein Synthesis and Sorting

With regard to translation in prokaryotes,the gene products are often encoded on polycistronic mRNAs.As a result,the quantities of each of the proteins are often graded,such that the first gene has a great deal of protein translated,whereas the last gene has very little.Which of the following features of prokaryotic translation may account for increased production of some products and decreased production of others?

Which of the following nucleotides in the anticodon can allow for "wobble" in translation?

In working with a potentially new antibiotic,you are attempting to determine where in prokaryotic translation this antibiotic has its effect.You have determined thus far that it interacts with a translational factor but need to identify which one.If this antibiotic interfered with elongation,which of the following factors could be a potential site of action?

The mRNA is translated in the 3' to 5' direction in

________ degrades mRNAs that contain no stop codons.

Which of the following statements is not true concerning peptidyl transferase?

________ degrades mRNAs that contain premature stops.

Ribosomes are very old structures,found in all organisms (except viruses),from bacteria to humans.As a result,molecular taxonomists are looking at relationships based upon which rRNA sequence(s)?

The ________ (enzymes)link amino acids with their appropriate tRNAs.

In eukaryotic initiation,one will often see the sequence ACCAUGG as a translational start sequence. This sequence is known as the ________ sequence.

Release factors of translation recognize the codon

The anticodon base ________ is able to bind U,C,or A,allowing for wobble in the anticodon region during translation.

The appropriate folding of a newly translated protein is essential,and chronic misfolding often leads to disease,especially in vertebrates.This misfolding,particularly in the case of prion diseases,may be due to a defect in

The newly arriving tRNA binds in the region of the ribosome known as the ________ site.

Of the following codons,which encodes a normal translational stop?

Discuss some of the possible ways in which nonsense mutations can potentially be suppressed in a cell.

Intramolecular protein splicing results in the formation of the final protein and the

The process by which cytosolic polypeptides are transported to a target organelle is via which of the following?

Messenger RNAs containing premature stop codons are destroyed by the mechanism of