Brainscape's Knowledge GenomeTM

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


See full index

BIOL1024 Fundamentals of Biochemistry > RNA synthesis > Flashcards

RNA synthesis Flashcards

1
Q

What subunit directs the E.coli RNA polymerase to the correct transcription initiation sites?

A

sigma

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

transcription

A

conversion of DNA into RNA

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

difference of RNA

A

use ribose sugar
no thymine but uracil
single stranded but can fold

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

mRNA

A

messenger
template for protein synthesis
heterogeneous length - average

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

rRNA

A

ribosomal

major component of ribosome

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

tRNA

A

transfer

carries amino acid in activated form to ribosome

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

snRNA

A

small nuclear - in RNA splicing

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

miRNA

A

micro
around 21 bases
bind to mRNA promoting degrade/inhibit their translation

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

how RNA is produced

A

copying strand of DNA as template - direct transcription 5’ to 3’ direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

producing other side

A

coding strand - 5’ to 3’ has same sequence as the RNA

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

catalyst for RNA synthesis

A

enzyme RNA polymerase

using rNTPs, release pyrophosphate

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

nucleotides

A

attached to 3’ -OH from 5’ to 3’ direction

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

DNA Duplex

A

around 17 base pairs

unwound

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

length of RNA-DNA hybrid duplex

A

8bp long

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

contain RNA polymerase

A

alpha*2, 2beta and omega - core enzyme

sigma - direct enzyme to start at initiation site

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

omega

A

stabilises within 5 subunits

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

sigma

A

initiation factor

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

how transcriptional units starts

A

marked by promoters

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

holoenzyme

A

6 subunit 450kDa

RNA polyermase

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

Pribnow box

A

a consensus sequence found at -10 on the non-template strand in bacterial promoter

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

consensus sequence

A

TTGACA

at -35

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

optimal sequence

A

best promoter site for RNA polymerase

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

If Pribnow box had G or C in it

A

harder for RNA polymerase to open up the transcription bubble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

direction of RNA synthesis

A

5’ to 3’

antiparallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is formed from RNA synthesis

A

Transient RNA/DNA duplex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

RNA polymerase size (how many bp)

A

able to bind to around 30bp of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

termination signals

A

palindromic GC rich regions followed by AT rich region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what the new RNA transcript forms

A

stem and loop

hair pin structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

when RNA transcript forms

A

RNA polymerase is kicked off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

protein factor p(pho)

A

signals for termination are in newly synthesised RNA rather than in DNA template

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

transcription and translation in prokaryotes

A

occurs at the same time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

after synthesis in prokaryotes

A

some RNAs are modified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

tRNA after synthesis in prokayotes

A

some bases and sugar are modified

CCA is added at the 3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

rRNA after synthesis in prokayotes

A

made as one long molecule - broken up into individual subunits by endo/exonucleases post transcriptionally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

synthesis in Eukaryotes

A

more complex due to transcriptional regulation

has nuclear membrane - separate transcription and translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

3 types of RNA polymerase

A

RNA polymerase I
RNA polymerase II
RNA polymerase III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

RNA polymerase I role

A

rRNA - 18s, 5.8s and 28s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

RNA polymerase II role

A

mRNA

39
Q

RNA polymerase III role

A

tRNA and 5s rRNA

40
Q

eukaryotes pre-mRNA processing

A

addition of poly A tail to 3’ end of RNA transcript

addition of cap to 5’ end - 5’-5’ triphosphate linked to 7-methyl-G

41
Q

increase in stability and specifies export to cytoplasm

A

acts as protector role
increase half life
interact binding protein

42
Q

eukaryote Pre-mRNA

A

contains introns and exons

43
Q

introns

A

non-coding section

44
Q

exons

A

coding region

45
Q

order of introns and exons

A

can not change

46
Q

proteins produced

A

may contain some exons and not others

47
Q

splicing site

A

coded by RNA sequence

48
Q

spliceosomes

A

splices the pre-mRNA

49
Q

importance of spliceosome

A

allows synthesis of different proteins from one gene - may be cell type specific

50
Q

example fibronectin

A

component of extracellular matrix

produced by fibroblast containing exons EIIIB and EIIIA

51
Q

liver cell in example for fibronectin

A

don’t encode the exons which allows fibronectin to be secreted and move freely in blood stream and help clot formation

52
Q

beta-thalassemia number of causes

A

has 3 ways of this causation

53
Q

beta-thalassemia first causation - change in nucleotide

A

single nucleotide change - destroying normal splice site - exonskipping

54
Q

beta-thalassemia second causation - extension

A

activation cryptic splice site - extended exon

55
Q

beta-thalassemia third causation - addition of new

A

causing of new exons to be incorporated - have extra exons

56
Q

control of transcription

A

gene expression need to be controlled to form proteins appropriate for tissue and its environment

57
Q

cause of enhancement by activators or blocked by repressors

A

the interaction of RNA polymerase and a promoter

58
Q

operon

A

in bacteria

promoter controls genes in common pathways

59
Q

lac operon - in bacteria

A

involved n metabolism of lactose

has lac Z, lac Y and lac A

60
Q

how to stop enzyme production

A

repressor gene binds to operator sequence - prevents transcription

61
Q

when is gene expressed

A

when RNA is transcribed into protein

62
Q

constitutive expression

A

genes expressed all the time

63
Q

regulated expression

A

genes expressed under certain conditions or time

64
Q

when lactose is present

A

allolactose binds to repressor protein which prevents binding to operator
therefore genes switched on and protein produced

65
Q

allolactose

A

inducer of operon

66
Q

can other operons be switched off

A

yes by other compounds

67
Q

example of other operons

A

trp operon

68
Q

trp operon

A

trp repressor binds to operator
in presence of compressors - switch off synthesis
in high presence of tryptophan

69
Q

regulatory gene

A

transcribed and translated to repressor protein or repressor inducer

70
Q

repressor protein

A

stop transcription

71
Q

repressor inducer

A

promote transcription

72
Q

control in eukaryotes complexity

A

tissue specificity
cell type specificity
development regulation

73
Q

transcription control

A

DNA packed - due to condensed chromatin

74
Q

modifying histones in transcription control

A

causes relaxation of region - exposing promoter-proximal element and promoter

75
Q

exposure of ppe and promoter

A

allows RNA polymerase to bind and transcribe sequence

76
Q

enhancers

A

found further up stream

binds to different transcription factor - bind to regulatory sequence close to start site

77
Q

DNA being able to fold back allows

A

formation of different forms to regulate gene expression of particular genes down stream

78
Q

advantage of DNA folding back to form different loops

A

help provide tissue selection and cell type

79
Q

Basal transcription factor

A

common in most genes

80
Q

function of Basal transcription factor

A

bind to promoter

such as TATA and CCAAT box

81
Q

Regulatory transcription factor

A

specific for particular gene - unique

cell type/ developmentally regulated

82
Q

Regulatory transcription factor function

A

bind to ppe and enhancer

83
Q

ppe

A

promoter-proximal element

84
Q

miRNA function

A

regulate gene expression

85
Q

characteristics of miRNA

A

small non-coding DNA - 21-25 nucleotide

86
Q

how miRNA is synthesised

A

as a precursor from nuclear DNA and processed into miRNA in nucleus and cytoplasm

87
Q

human genome encode for miRNA

A

> 1000 miRNA

88
Q

function of miRNA

A

base pairing complementary sequences in mRNA

silencing specific mRNA and repressing protein translation

89
Q

miRNA expression

A

in element close by such as introns

90
Q

miRNA processing

A
  • form pri-miRNA using RNA pol II forming stem loop structure
  • processed by Drosha and Pasha - trim different components to form Pre-miRNA
91
Q

miRNA processing out of nucleus

A
  • using Dicer to form miRNA/ antisense miRNA duplex

which then binds to coding mRNA = rapid degradation

92
Q

after processing

A
  • interfering RNA induced in silencing complex

- targeting mRNA by relying on complementary base pairing

93
Q

product of targeting mRNA

A

cleave off the target RNA
translation repression and then destruction of RNA
formation of heterochromatin on DNA (target RNA being transcribed)

BIOL1024 Fundamentals of Biochemistry (25 decks)

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