BIO 121 EXAM 2 REVIEW

These proteins are required for transcription of all genes expressed in all cells, regardless of cell-type.

• Promoters

• TFII Transcription Factors

• Tissue Specific Transcription Factors

• RNA Pol II

• B and D

This is the regulatory region of DNA that can be found upstream, downstream, or within introns of genes.

• Exons

• Promoters

• TFIIs

• Enhancers

Fzd5 is a gene that is normally expressed in intestinal Paneth cells, but not in absorptive cells. How is Fzd5 normally expressed in Paneth cells, but not absorptive cells?

• The Fzd5 enhancer is present in the genome of Paneth cells, but not absorptive cells

• There is a Tissue Specific (TS) transcription factor expressed in Paneth cells that promotes Fzd5 transcription, but there is no such TS transcription factor in absorptive cells

• The Fzd5 gene is not present in the genome of absorptive cells

You are a molecular biologist working in a lab. You want to induce (i.e. force) the expression of Fzd5 in absorptive cells. How could you do this?

• Introduce the TS transcription factor from Paneth cells (that binds to the Fzd5 enhancer) in absorptive cells

•   Introduce RNA Pol II in absorptive cells

•   Remove Fzd5 promoter sites from Paneth cells 

•   Add the Fzd5 enhancer (present in Paneth cells) to the absorptive cells 

Which of the following statements about TF II transcription factors is false?

•   TFII transcription factors bind promoters 

•   TFII transcription factors transcribe genes 

•   TFII transcription factors are found in all eukaryotic cells and are required for transcription 

•   TFII transcription factors help recruit RNA Pol II to the promoter 

Which of the following is required for Nonsense Mediated Decay to occur?

• A frameshift mutation in the open reading frame

• A shortened Poly A tail

• Detection of a premature termination codon upstream of an EJC (Exon Junction Complex)

• Protein misfolding resulting from failed attempts by chaperone proteins

• C and D are both correct

You are examining the expression of a gene called DISC1 in a neuron. You notice that the cell transcribes the DISC1 gene and produces nRNA, but there is no DISC1 protein present. Which of the following NOT a possible explanation?

• A nonsense mutation in the coding sequence caused the mRNA to be degraded

• A miRNA prevented association of the mRNA with translation machinery

• A miRNA recruited a protein-digesting enzyme (protease) to the mRNA.

• eIFs did not get recruited to the mRNA

• None of the above (all could explain the lack of DISC1 protein)

You are examining a cell that has a very high amount of casein. What is the most likely cause of the increase in casein?

• Exposure to prolactin prevented the 5’ cap from forming on the casein nRNA

• The casein nRNA was differentially spliced to produce various isoforms

• Exposure to prolactin prevented the formation of the casein mRNA poly-A tail

• Prolactin increased expression of an miRNA that binds the casein mRNA transcript

• Exposure to prolactin increased the length of the casein mRNA poly-A tail

A protein is being synthesized in the cytosol. It begins to misfold during translation because all of the hydrophobic residues are inappropriately interacting with other residues. Which of the following proteins is not functioning properly?

• Calnexin

• Calreticulin

• Hsp70

• Hsp60

• C and D are correct

You are examining a group of cells that has very high amounts of protein aggregates. You are making a list of proteins that could be improperly functioning, and thereby causing this defect. Which of the following proteins should NOT be on your list?

• Calnexin

• Hsp60

• Hsp70

• Proteasome

• None of the above (all of these should be on the list)