transcription 5

Question 1

what does the phosphorylation of the C-terminal domain allow

Answer 1

loading of rna processing machinery

Question 2

what are the 5 alterations done to rna transcript

Answer 2

• 5’ cap added
• 3’ processing and polyadenylation
• splicing
  -editing
  -transport

Question 3

what is splicing

Answer 3

removal of introns

Question 4

how do we know what is an exon and an intron

Answer 4

they have conserved motifs that indicate the start and end

Question 5

what reaction are introns removed by

Answer 5

transesterification

Question 6

how is the 5’ splice site cleaved

Answer 6

the OH group from the branch point attacks the 5’ splice site

Question 7

what happens to the intron when the 5’ is spliced

Answer 7

the intron will fold back on itself

Question 8

how do we cleave the 3’ splice site

Answer 8

the OH from the 5’ site attacks the 3’

Question 9

what splices the gene and when is it produced

Answer 9

spliceosome
assembled as the gene is transcribed

Question 10

what is a spliceosome made of and what does it use

Answer 10

rna and protein which form snRNPs
atp

Question 11

what will the snRNPs contain

Answer 11

a complementary strand the splice site

Question 12

what are the three steps of rna splicing

Answer 12

• commitment/ early complex
• pre-spliceosome/ complex a
• spliceosome formation

Question 13

what binds at the 5’ splice site

Answer 13

U1 snRNP

Question 14

what binds at the branch point

Answer 14

branch point binding protein

Question 15

what binds at the 3’ splice site

Answer 15

U2AF35

Question 16

what will happen in step 2

Answer 16

u2 snrnp binds to branch site and creates a buldge

Question 17

what will happen in step 3

Answer 17

u 4, 5 and 6 bind and brings the splice sites together

Question 18

what are the three types of rna splicing

Answer 18

• nuclear pre-mrna splicing
• group 1 self-splicing
• group 2 self- splicing

Question 19

what are two errors that can occur in splicing

Answer 19

-exon skipping
-cryptic splice site

Question 20

what proteins are important for splice site selection

Answer 20

SR proteins

Question 21

what are the sr proteins that bind to sequences

Answer 21

exonic splicing enhancers

Question 22

what is alternative splicing and what does it lead to

Answer 22

when rna can be spliced in more then one way and can lead to 2 or more proteins from the same gene

Question 23

what is rna editing

Answer 23

when information changes at the level of mrna

Question 24

when would gene editing be needed within the liver

Answer 24

when a stop codon is needed to stop making amino acids

Question 25

what enzyme converts cytosine to uracil

Answer 25

cytosine deanimase

Question 26

when is rna editing needed in the ns

Answer 26

when converting in glutamine receptors from glutamine to arginine

Question 27

what disease causes low beta globin amounts in haemoglobin

Answer 27

beta thalassemia

Question 28

what is beta thalassemia caused by

Answer 28

mutations in the tata bo, 3' and coding region