Biochem 73

Question 1

What is the major RNA product of eukaryotic RNA Polymerase I?

Answer 1

rRNA

Question 2

What is the major RNA product of eukaryotic RNA Polymerase II?

Answer 2

mRNA

opens DNA at promoter site

Question 3

What is the major RNA product of eukaryotic RNA Polymerase III?

Answer 3

tRNA

Question 4

Alpha-amanitin (from death cap mushroom) causes severse hepatotoxicity through?

Answer 4

Inhibiting RNA polymerase II -> stopping of mRNA synthesis

Question 5

What RNA polymerases are found in prokaryotes?

Answer 5

They only have 1 multisubunit complex RNA Polymerase which makes all 3 type of RNA.

Question 6

What is Ricin?

Answer 6

a potent toxin that inhibits protein synthesis by cleaving the rRNA component off the eukaryotic 60s subunit.

Question 7

What is hnRNA?

Answer 7

Heterogenous nuclear RNA. Essentially pre-mRNA (Before modification)

Question 8

What 3 processes occur in the nucleus in regards of post translational modifications?

Answer 8

1) Capping of 5’ end (addition of 7-methylguanosine cap)
2) Polyadenylation of 3’ end (about 200 A’s)
3) Splicing out of introns

Question 9

What is the role of cytoplasmic P bodies?

Answer 9

Instead of associating with ribosomes for translation, some mRNA molecules interact proteins found in P bodies.

Functions:

1) translation repression
2) form of mRNA storage

Question 10

What is found within cytoplasmic P-bodies? (3)

Answer 10

1) micro-RNA
2) Exonucleases
3) decapping enzymes

Question 11

What is the polyadenylation signal?

Answer 11

AAUAAA

Question 12

Polyadenylation of 3’ end occurs via which enzyme?

Answer 12

Polyadenylate polymerase complex

Question 13

Antibodies to spliceosomal snRNP’s are highly specific for what?

Answer 13

SLE

aka: anti-Smith antibodies

Question 14

Anti-U1 RNP antibodies are highly associated with what?

Answer 14

Mixed connective tissue disease.