Brainscape's Knowledge GenomeTM

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


See full index

Genetics and Molecular Biology > Bentzen 5 - Transcription > Flashcards

Bentzen 5 - Transcription Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What are the two genetic processes that lead to ‘expression?’

A

Transcription and translation

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

What is the difference between gene expression processes in eukaryotic cell and prokaryotic cells in terms of mRNA?

A

A single strand of RNA can be transcribed and translated at the same time in prokaryotes. In eukaryotes it goes through RNA processing between transcription and translation.

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

What types of RNA do eukaryotes and prokaryotes share?

A 
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What types of RNA do eukaryotes have, and prokaryotes not have?

A 
pre-messenger RNA (pre-mRNA)
Small nuclear RNA (snRNA)
Small nucleolar RNA (snoRNA)
Small cytoplasmic RNA (scRNA)
MicroRNA (miRNA)
Small interfering RNA (siRNA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is transcription?

A

The SELECTIVE synthesis of RNA from DNA.

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

Is all DNA transcribed in a given cell?

A

no

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

What way is the template read in transcription?

A

3’ to 5’ direction

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

What group are ribonucleotides added to in transcription?

A

The 3’ OH group of the GROWING chain.

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

In what direction is RNA synthesized in in transcription?

A

The 5’ to 3’ direction

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

Can a DNA strand have multiple RNA molecules being synthesized from it at once?

A

Yes, think Christmas tree picture.

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

Is there a requirement for 3’ OH in RNA transcription?

A

NO

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

How many strands of DNA are involved in RNA transcription?

A

One strand, not both

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

How much of the genome is replicated in DNA replication?

A

The whole genome

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

How many time does DNA replicated? How many times does transcription occur?

A

DNA replicates once in the S stage of a cell’s life cycle. Transcription occurs many time.

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

Do DNA replication and transcription proceed in the same direction or a different direction? What direction do each go in?

A

Both go in the same direction, 5’ to 3’

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

What are three requirements for transcription?

A
  1. RNA nucleoside triphosphates (rNTPs)
  2. DNA template
  3. RNA polymerase and other proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the components of a ribonucleoside 5’ triphosphate (rNTP)

A

A triphosphate attached to the 5’ carbon of a ribose sugar. A base attached to the 1’ carbon on the ribose sugar ring.

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

What is a transcription unit?

A

A gene. A region of DNA that codes for a RNA molecule and the sequences necessary for transcription.

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

What are three critical regions of a transcription unit (gene)?

A

Promotor

RNA coding region

Termination site

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

Where is the promotor region of a transcription unit found?

A

Upstream of start site, adjacent to gene.

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

What does downstream (+) of gene mean?

A

Direction moving from start site +1 to the end of the transcription termination site +____

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

What does upstream (-) of gene mean?

A

Moving further away from promotor and not crossing through gene. Eg. Upstream - promotor - gene - terminator

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

Where is the RNA coding region?

A

Downstream of the start site

24
Q

Where is the termination site

A

Downstream of start site

25
Q

What is the ardor of a transcription unit (list all 5 sites and downstream/upstream)

A

Upstream (-) - promotor - transcription start site (+1) - RNA coding region - terminator - transcription termination site - downstream

26
Q

What is the promotor of the transcription unit?

A

A DNA sequence that is recognized and bound by the transcription apparatus (RNA polymerase plus other proteins).

27
Q

What indicates the direction of transcription?

A

The promotor

28
Q

What are consensus sequences?

A

Short stretches of DNA in promotors that are conserved among promotor of different genes. Binding of transcription apparatuses to these sequences orients the RNA polymerase towards the start site

29
Q

What is the most common consensus sequence?

A

The Pribnow box at -10 and -35 nucleotides upstream of the start site. -35 and -10 elements are not identical in all promotors

30
Q

What does a slash (/) mean in base sequences?

A

That the bases involved have equal frequency

31
Q

Each -35 and -10 sequence is a variation on a ____

A

consensus sequence

32
Q

What does variation of sequence at -35 and -10 regions of promotors affect? What is the consequence of this effect?

A

Variation effects the strength of the promoter.

Strength = the frequency of transcription
- The more closely the sequence resembles the consensus sequence, the stronger promoter it is

33
Q

What is an UP mutation of a promotor region at -35 and/or -10?

A

Making the sequence more closely resemble the consensus sequence. Strengthens it

34
Q

What is a DOWN mutation of a promotor region at -35 and/or -10?

A

A down mutation makes the sequence less similar to the consensus sequence and therefore weakens the promoter

35
Q

What unit does RNA polymerase use to synthesize RNA?

A

ribonucleoside 5’ triphosphates

36
Q

What type of complex is RNA polymerase?

A

A multi protein complex

37
Q

What does RNA polymerase catalyze

A

It catalyzes the formation of phosphodiester bonds

38
Q

What does RNA polymerase do to DNA?

A

It unwinds the DNA duplex

39
Q

How many RNA polymerases do prokayotes have? eukaryotes?

A

Prokaryotes have a single RNA polymerase

Eukaryotes have three or more seperate RNA polymerases

40
Q

Many bacteria have multiple types of sigma factors, what are these?

A

Help in the recognition of multiple classes of promoters. Binds to the RNA protein-complex, allows for selective polymerization. Without it, the core enzyme initiates transcription randomly.

41
Q

What is the holoenzyme RNA polymerase?

A

The complete enzyme complex composed of the core RNA polymerase and the sigma factor.

RNA transcription is initiated when core RNA polymerase binds to the promoter with the help of sigma

42
Q

When does transcription of RNA end (what sequence).

A

Transcription ends AFTER a terminator sequence is transcribed

43
Q

What are the two major types of terminators in bacteria?

A

Rho-dependent (requires Rho protein)

Rho-independent

44
Q

What happens with transcription of Rho-independent terminators?

A
  1. There are inverted repeats of DNA
  2. polymerases pauses at U’s
  3. The RNA transcript being made forms a hairpin formation with the inverted sequence
  4. RNA transcript dissociates from RNA polymerase, DNA reanneals

Transcription terminates when inverted repeats from a hairpin followed by a string of uracils

45
Q

Describe Rho-dependent termination

A
  1. Rho binds a stretch of RNA upstream of the terminator
  2. RNA polymerase pauses when it reaches the terminator seuqnce and Rho catches up
  3. Rho unwinds DNA-RNA hybrid using helicase activity
46
Q

Which eukaryotic RNA polymerase transcribes pre-mRNA?

A

RNA polymerase II

47
Q

What are the two components of a eukaryotic RNA polymerase II promoter?

A

Core promotor + regulatory promotor

48
Q

What is the core promoter of RNA polymerase II in eukaryotes?

A

It is the minimal sequence required for accurate transcription initiation.

49
Q

Where is the core promoter of RNA polymerase II found?

A

It extends upstream/downstream of transcription start site.

50
Q

What are the components of the core promoter sequence in RNA polymerase II promoter?

A

Includes a number of consensus sequence (common elements include TFIIB, TATA, initiator and DCPE) for transcription factor binding

The initiator element of the core promoter is +1 and the TATA box is -25

51
Q

What is the regulatory promoter of RNA polymerase II promoter? Where is it found?

A

Located upstream of the core promoter. It has consensus sequence that transcriptional activator proteins bind to and effect the rate of transcription.

52
Q

What are the 3 components of the eukaryotic basal transcription apparatus? What is it?

A

RNA polymerase II

General transcription factors (TF)

Mediator protein

It’s necessary for transcription at minimal or basal levels.

53
Q

Where does the basal transcription apparatus bind in eukaryotes?

A

Binds to core promoter near transcription start site.

54
Q

How is the rate of transcription regulated at the level of teh basal transcription apparatus?

A

Additional regulatory proteins (eg. transcriptional activator proteins) bind to the regulatory promoter and enhancer sequences to affect the rate of transcription

55
Q

Describe the assembly of the Basal transcription apparatus

A
  1. A TATA binding protein binds to the TATA box on the core promoter
  2. General transcription factors and mediators bind around RNA polymerase II and the core promoter
56
Q

How is RNA polymerase II transcription terminated?

A

Transcription does not end at a specific sequence.

  1. There is cleavage of the mRNA at a specific site
  2. A 5’ to 3’ exonuclease degrades the remaining mRNA, terminating transcription

Genetics and Molecular Biology (23 decks)

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