Lippincott - RNA Structure, Synthesis, Processing Flashcards Preview

[OS 201] 3rd Exam > Lippincott - RNA Structure, Synthesis, Processing > Flashcards

Flashcards in Lippincott - RNA Structure, Synthesis, Processing Deck (35)
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1

3 major types of RNA participating in protein synthesis

tRNA
mRNA
rRNA

2

difference of RNA from DNA

[1] contain ribose instead of deoxyribose
[2] contain uracil instead of thymine
[3] exist as single strands
[4] capable of folding into complex structure

3

rRNA

components of ribosomes

4

rRNA species in eukaryotic cells

28S, 18S, 5.8S, 5S

5

tRNA

carries amino acids to be used in translation

6

mRNA

[1] carries genetic information from nuclear DNA to the cytosol
[2] used as a template for protein synthesis

7

steps in RNA synthesis

[1] initiation
[2] elongation
[3] termination

8

important event in initiation

binding of RNA polymerase to promoter

9

direction of transcription

5'-->3'

10

3 types of RNA polymerase in eukaryotes

RNA polymerase I, II, III

11

RNA polymerase I

synthesizes precursor of 28S, 18S, 5.8S rRNA

12

RNA polymerase II

synthesizes mRNA precursors

13

RNA polymerase III

synthesizes tRNA, 5S rRNA, snRNA, snoRNA

14

promoter and consensus sequence for RNA polymerase II

TATA box, CAAT box

15

other name for TATA box

Hogness box

16

TFIID

recognizes and binds the TATA box

17

TFIIF

brings polymerase to promoter

18

TFIIH

[1] helicase activity melts DNA
[2] kinase activity phosphorylates polymerase, allowing it to clear the promoter

19

GC box

found in genes that are constituitively expressed

20

enhancers

[1] cis-acting DNA sequences that increase the rate of initiation of transcription by RNA polymerase II
[2] contain response elements that bind specific TFs that are transcription activators

21

posttranscriptional modifiers of rRNA [2]

[1] ribonucleases
[2] exonucleases

22

enzyme that adds CCA sequence to tRNA

nucleotidyltransferase

23

where is the CCA sequence in tRNA attached?

3' end

24

major posttranscriptional modifications to mRNA [3]

[1] 5' capping
[2] addition of poly A tail
[3] splicing

25

composition of 5' cap

7-methylguanosine

26

linkage of 5' cap

5'-->5' triphosphate linkage

27

enzymes in addition of 5' cap

[1] guanylyltransferase - adds GMP
[2] guanine-7-methyltransferase - methylates GMP

28

composition of poly A tail

40-200 adenosine nucleotides attached to 3' end

29

enzymes in addition of poly A tail

polyadenylate polymerase

30

function of poly A tail [3]

[1] stabilize the mRNA
[2] facilitate exit from nucleus
[3] aid in translation