Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacy Y2- Exam 3 > DNA mutation and repair- part 2 > Flashcards

DNA mutation and repair- part 2 Flashcards

1
Q

what direction is the the new DNA template strand made in using RNA polymerase?

A

5’-3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does RNA polymerase I do?

A

transcribes most rRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does RNA polymerase II do?

A

transcribes all protein coding genes and some small nuclear RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does RNA polymerase III do?

A

transcribes tRNA genes, 5’s rRNA and genes for some small structural RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is required for all promoters to help RNA polymerase II?

A

basal transcription factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

during a bacterial infection the cytokine TNF is produced an present in high conc with 2hrs in the plasma. How can many produced at once?

A

amplification during transcription and due to the action of polyribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is amplification?

A

transcribing many identical mRNA very quickly they can then synthesis several identical proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are 3 environments that can stimulate gene transcription?

A

inflammation
chemicals
mechanical stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are some environments that can stimulate gene transcription?

A 
inflammation
chemical insults
drugs
disease
nutritional status
mechanical stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which TF pulls the double helix apart at the start site allowing transcription to begin?

A

TFIIH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what do gene regulatory proteins do?

A

they bind to specific DNA sequences they are either enhancers or suppressors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is a pribnow box?

A

the repressor binding site on the DNA sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the pathway for allowing transcription to occur?

A

molecular signal comes from outside and activates the activator protein that then binds to the specific sequence in the promotor which allows transcription to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does a repressor prevent transcription from occurring?

A

if a repressor is sat in the repressor region when a signal comes in it knocks the repressor off and transcription will occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

where are enhancers normally found?

A

in the major groove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

can repressors bind to enhancer regions?

A

yes even though activator proteins bind there too, in order to prevent activators from binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what do co-activators do?

A

they bind to activator proteins/TF and induce or enhance gene transcription. They dont bind to DNA they express histone deactylase activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is capping?

A

on the 5’ end when the addition of a guanine with a methyl group making the molecule more stable and protects the molecule from RNases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is polyadenylation?

A

at the 3’ end it cleaves and around 250 adenines are added , improves stability to the molecule and also involved in translation initiation. protects from mRNA from degradation from exonuclease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does splicing occur?

A

snRNA proteins come together in a spliceosome and cuts out the intron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where does translation take place?

A

in the cytoplasm and ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the start codon?

A

methionine (AUG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a codon?

A

3 base units of the code

24
Q

what molecule translates mRNA into proteins?

A

tRNA

25
Q

what are the 2 important sites on tRNA molecules?

A

amino acid binding site and anticodon region

26
Q

why is the anticodon region important?

A

because it is complementary to the codon on the mRNA and encodes the codon for the amino acid at the top of the tRNA molecule

27
Q

what is the structure of tRNA?

A
  • around 80 nucleotides long

- clover structure with 4 short segments and its a double helical

28
Q

what enzyme covalently bond the amino acid to the right tRNA molecule?

A

aminoacyl tRNA synthetase

29
Q

what is rRNA?

A

its produced from DNA template in the nucleolus and it combined with proteins into large and small ribosomal subunits

30
Q

what are the different binding sites on a ribosome?

A

E site- exit
P site- peptide
A site- amino acid

31
Q

rRNA molecules combine with how many proteins to form a complex known as a ribosome?

A

50 proteins

32
Q

which subunit catalyses the formation of peptide bonds that link amino acids together?

A

large subunit

33
Q

what is the responsibility of the small subunIt on the ribosome?

A

matching the mRNA to the codon on the tRNA

34
Q

what are the 3 main stages of translation?

A

-initiation, elongation and termination

35
Q

what needs to occur for translation to happen? steps?

A
  • mRNA migrates to rough ER
  • associates with the rRNA of a ribosome
  • ribosome reads the infor
  • ribosome directs various species of tRNA to bring in their specific amino acid fares
  • tRNA specified is determined by the code being translated in the mRNA
36
Q

what happens during elongation?

A

-new tRNA come and join on their amino acid to growing polypeptide chain

37
Q

what happens during termination?

A

due to the stop codon a release factor comes and releases the polypeptide chain

38
Q

what is a polyribosome?

A

when there is more than one ribosome at least 80 nucleotides apart working along an mRNA molecule

39
Q

what are initiation factors?

A

factors that will bring all the needed components for initiation togther to allow it to occcur

40
Q

what is needed from the initiator tRNA molecule?

A

always has UAC anticodon
always carries amino acid methionine
capable of binding to the P site

41
Q

what does tetracycline do?

A

it inhibits protein syntheiss in bacteria by blocking binding of aminoacyl tRNA synthase to A site on ribosome

42
Q

what does chloramphenical do?

A

its inhibits protein synthesis in bacterial ribosomes by blocking peptidyl transfer by does not affect cytosolic protein synthesis in eukaryotes

43
Q

what does streptomycin do?

A

causes mis-reading of genetic code in bacteria

44
Q

what does erythromycin do?

A

blocks movement of mRNA through the small ribosomal subunit

45
Q

what does rifamycin do?

A

inhibits initiation of RNA chains by binding to RNA polymerase

46
Q

what is used to encourage protein folding ?

A

energy and molecular chaperones to prevent mis-folding

47
Q

what are some post-translational modifications that may occur?

A
  • proteolysis
  • glycosylation
  • insertion of cofactors
  • formation of disulfide bonds
  • phosphorylation
48
Q

what is proteolysis?

A

removal of signal sequences by hydrolysis of peptide bond and enzyme activation of pro-enzymes

49
Q

what are signal sequencing ?

A

when proteins are are directed to a specific site for their function

50
Q

what is glycosylation?

A

the process of oligosaccharides covalently linked to amino acids to form glycoproteins.

51
Q

what determines a proteins turnover (halflife?

A

its N-terminal residue, some PEST proteins are more rapidly degrade that other proteins

52
Q

what enzyme is involved in all protein degradion pathways?

A

protease

53
Q

what is a non-specific degradation pathway?

A

where protease called cathepsins are present in lysosomes

54
Q

what proetin is involved in the ATP-dependant pathway for protein degradation?

A

ubiquitin

55
Q

what amino acid doe sthe ubiquitin bind to in the protein it wants to degrade?

A

a leucine

56
Q

what needs to happen for ubiqutin to work?

A

4 or more ubiquitin molecules need to bind - polyubiquinctinated in a chain so the protein can be targeted by proteasomes

Pharmacy Y2- Exam 3 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions