RAT #12 - Regulating Protein Synthesis

Question 1

To function as a repressor-binding site, the iron response element (IRE) must be in the 5-UTR region of the ferritin mRNA. This suggests that regulatory protein binding to this IRE does what?

a. blocks the translation start site

b. regulates mRNA degradation
c. inhibits the translocation step of translation
d. promotes circularization of the mRNA template

Answer 1

a. blocks the translation start site

Question 2

A process called alternative splicing of mRNA transcripts can produce mRNAs with ________ from the same gene.

a. one different exon

b. more or fewer exons
c. completely different exons

d. all of the above

Answer 2

no answer given

Question 3

{True / False}

The presence of an Iron Response Element affects translation of every mRNA transcript.

Answer 3

FALSE

Question 4

Phosphorylation of eIF2:

a. prolongs elongation

b. enhances translation
c. inhibits translation
d. has no effect on translation

Answer 4

c. inhibits translation

Question 5

The Half-life of an mRNA molecule is primarily or predominantly dependent on which of the following transcript structures?

a. poly-A tail

b. 5’-UTR
c. the coding region

d. the 5’-cap

Answer 5

INCORRECT

d. the 5’-cap

Question 6

The 7-methyl guanosine cap and the poly-A tail of a mRNA are both involved in or required for?

a. protecting an mRNA from exonuclease attack
b. protecting an mRNA from endonuclease attack
c. alternative splicing
d. miRNA activity

Answer 6

a. protecting an mRNA from exonuclease attack

Question 7

{True / False}

Small nucleotide sequences such as siRNA or miRNA are involved in BOTH post- transcriptional and translational regulation of gene expression.

Answer 7

TRUE

Question 8

Phosphorylation of Elongation Factors 2 (EF2) and 2B (EF2B):

a. allows them to initiate translation

b. allows them to be recycled back to the ribosome
c. blocks the addition of a terminal phosphate to the bound GDP

d. blocks their exchange of bound GDP for GTP

Answer 8

d. blocks their exchange of bound GDP for GTP

Question 9

Phosphorylation of eIF4E:

a. Enhances Translation
b. Inhibits Translation
c. Has NO effect on Translation
d. Activates Iron Response Elements

Answer 9

a. Enhances Translation

Question 10

{True / False}

Messenger RNAs have varying Half-Lives in the Cytoplasm.

Those Differences are usually due to Differences in Sequences near 5’-end of the mRNA.

Answer 10

NO ANSWER GIVEN