Exam 19: Gene Expression: Iiprotein Synthesis and Sorting

You discover a pattern of a 20 amino acid sequence at the C-terminus of over 50 proteins in an organism.You hypothesize that this amino acid sequence is a signal sequence for localization into a specific organelle or cell compartment,but you don't know which one.How might you use microscopy to investigate the location of proteins with this unique C-terminus sequence?

The unfolded protein response slows the production of ________ and increases the ________.

In eukaryotes,the 3ʹ end of the mRNA is important in the initiation of translation because

Within the endoplasmic reticulum,________ recognizes misfolded or unassembled proteins and transports them back to the cytosol.

During elongation,each newly arriving tRNA binds in the region of the ribosome known as the ________ site.

The transfer of polypeptides into the ER is called

Using the techniques of genetic engineering,you design a protein you want to accumulate within the ER of yeast cells.To accomplish this goal,you need to

Segments of polypeptides that are retained following protein splicing are called

Peptide bond formation is catalyzed by an RNA molecule in

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

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

You want to clone a eukaryotic gene and express the corresponding protein in yeast.However,the protein typically localizes within mitochondria.How will you perform your gene cloning so that the protein is secreted from the cell,rather than localized within yeast mitochondria?

Polycistronic mRNAs encode

In which of the following groups are most mRNAs monocistronic?

The codon for phenylalanine is UUU.Which of the following codons also most likely encodes for phenylalanine?

You have cloned a eukaryotic gene,and inserted it into a bacterial system for expression.You discover that the gene product is much longer than should be observed based upon the insert you successfully cloned.What problems would result in a longer cloned sequence? How will you go about investigating your hypothesis? Would your answer change based upon the presence or absence of introns? Why or why not?

Which of the following organelles does not receive proteins by posttranslational import of proteins synthesized on cytoplasmic ribosomes?

The initial amino acid incorporated into a nascent peptide is N-formylated in

Messenger RNAs that contain no stop codons are eliminated by

The presence of a transit sequence directs a protein from the ________ to the ________.