Brainscape's Knowledge GenomeTM

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


See full index

Quiz 2 > Q2-FUN11/Transcription and regulation of gene expression > Flashcards

Q2-FUN11/Transcription and regulation of gene expression Flashcards

1
Q

At what steps of transcription does regulation occur at?

A
  1. chromatin structure
  2. transciption initiation
  3. mRNA stability
  4. transcript processing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 major functions of RNA within the cell?

A

copying genetic info from DNA, helps make ribosomes, help build new polypeptides

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

The structure of DNA is _____ while the structure of RNA is _________

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

DNA is located in the _______ while RNA is located in the _________

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

What types of RNAs are involved in transcription and translation?

A

mRNA, rRNA, tRNA

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

What are snRNAs?

A

small nuclear RNAs, they function in a lot of nuclear processes, inc. splicing pre-mRNA

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

What are ncRNAs?

A

they are non-coding RNAs. They function is a lot of different cellular processes, including

-regulation of gene expression.

  • X-chromosome inactivation
  • protein transport.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What distinct signals are encoded within the DNA sequence of a gene?

A

start and stop

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

Where does transcription start and end at?

A

it starts at the transcription start site (TSS, located at the end of the promoter region) and ends at the terminator site.

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

Each gene has a _________ promoter

A

unique

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

What are the two types of promoters?

A

basal promoter element and enhancer element

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

What is an enhancer?

A

Enhancers are regulatory DNA sequences that, when bound by proteins called transcription factors, enhance the transcription of a gene.

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

What is a basal promoter?

A

it is bound by RNA poly II and basal transcription factors

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

What is an example of a basal promoter?

A

TATA box - most common

2-30 base pairs from transcriptional site

can bind basal TFs and RNA poly II

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

What typically catalyses transcription?

A

RNA poly II

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

How does RNA poly II work?

A

it transcribes one of the 2 DNA strands of the gene. it reads its template from 3’ to 5’ and makes an RNA copy of 5’ to 3’.

It incorportates AGCU when making the mRNA copy of the DNA

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

What are the 3 stages of transcription?

A

initiation, elongation, termination

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

What happens in initiation of transcription?

A

RNA poly II binds to DNA and unwinds a 17-18 bp segment of the promoter. This segment is called the open complex.

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

Explain what happens during elongation of transcription.

A

RNA Pol II moves along the template until it reaches the terminator region. During this phase, an area of DNA under the RNA pol II stays unwounded. This unwounded part is called the transcription bubble and it moved along the DNA.

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

What 2 things happen during temination?

A
  1. transcription continues beyond the protein coding region (3’ UTR)
  2. endonuclease (enzyme that cleaves mRNA) cleaves abt 20 base pairs beyond the sequence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the primary transcript?

A
22
Q

What are hnRNAs?

A

heterogenous nuclear RNA. bulk of transcribed RNAs that hasnt been processed

(processed means hasnt been 5’ capped and no poly A tail)

23
Q

What are the 2 types of post translational mRNA processing?

A

5’ capping and 3’ poly A tail

24
Q

explain 5’ capping.

A

add a 7-methyl-guanosine residue to the 5’ end of the mRNA.

the mRNA is catalysed by guanylyltransferase (capping enzyme) and then methylated by a methyltransferase enzyme

the 1st and 2nd nucleotides are also methylated

25
Q

Why is 5’ capping important?

A

it protects the mRNA from degraded by exonucleases, promotes nuclear export, helps with the recognition of translational machinery

26
Q

explain the 3’ poly A tail addition to the primary transcript.

A

after the polyadenylation signal sequence has been recognized (and endonuclease has been recruited and mRNA has been cleaved), Poly(A) polymerase adds abt 40-250 adenines to the cleaved 3’ end

27
Q

What determines the stability of mRNA?

A

3’ UTR (untranslated region) sequence determines the stability of mRNA

28
Q

What is the poly A tail on an mRNA transcript stabilized by?

A

poly-A binding protein (PABP), binds approx 30 residues

29
Q

What happens to the poly A tail over its lifetime?

A

it gets gradually shortened

30
Q

What happens when the PABP can no longer bind?

A

the 30 base pairs get degraded

31
Q

Which part of the mRNA transcript gets spliced out?

A

introns get spliced out

32
Q

what carries out the splicing of introns in an mRNA transcript?

A

spliceosome

33
Q

what is a spliceosome made out of?

A

large comple of RNA and proteins, small nuclear RNAs + proteins = small nuclear ribonuceloproteins (snRNPs)

34
Q

what do snRNP’s do?

A

the facilitate splicing by located specific seqences at the end of each intron, cutting them out, and rejoining the exons together

35
Q

explain how snRNP’s work.

A
36
Q

Explain differential splicing/exon shuffling.

A

it is a way for a single primary transcript to be spliced into different mRNAs, by the inclusion of diff sets of exons

https://www.youtube.com/watch?v=JEylX4cQvpg

37
Q

What are the 2 types of genes?

A

constitutive genes and inducible genes

38
Q

Are constitutive genes essential?

A

yes they are essential and nessessary for life

39
Q

Are constitutive genes constantly expressed or only on some of the time?

A

since they are nessessary for life, they are continuously expressed

40
Q

What are inducible genes?

A

inducible genes are genes that only need to be turned on some of the time when they are required

41
Q

What do inducible genes determine?

A

development and tissue specificity

42
Q

What do inducible genes allow cells to do?

A

they allow cells to respond to the environment

43
Q

Inducible gene expression is controlled by _________________ proteins

A

transcription factor

44
Q

what is an example of Inducible gene expression is controlled by transcription factor proteins?

A

steroid hormones bind to steroid receptor transcription factors. these form a homodimer that finds and binds to certain DNA sequences

45
Q

transcription factors are proteins that bind to a specific ________ in the gene promoter

A

DNA sequence

46
Q

Transcription factors control the rate of ______

A

transcription

47
Q

What on the transcription factor determines the rate of transcription?

A

binding sites

48
Q

What do miRNAs do?

A

they are small strands of RNA (20-25 nucleotides) that regulate gene expression

49
Q

miRNAs are transcribed from _____________

A

DNA

50
Q

do miRNAs make proteins?

A

no they are non-coding RNA

51
Q

the primary function of miRNA is to ________ gene expression

A

down regulate

52
Q

what are the 2 ways miRNA blocks gene expression?

A

it promotes RNA degradation by binding to complementary sequences in 3’ UTR and induces degradation

it binds to mRNA and blocks translation

Quiz 2 (18 decks)

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