Brainscape's Knowledge GenomeTM

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


See full index

*MCD NAGE Y1* > Gene Transcription > Flashcards

Gene Transcription Flashcards

1
Q

What is the name for genes transcribed in all cells?

A

Housekeeping genes

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

How many types of RNA Polymerase are there?

A

3

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

Which types of RNA do each type of RNA polymerase transcribe?

A

I: rRNA
II: mRNA
III: tRNA and 5S RNA

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

What are the proteins that bind to DNA to regulate transcription?

A

Transcription Factors

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

What is the template strand also known as?

What does this mean?

A

Antisense Strand
The DNA that gets transcribed: anti as its the opposite of the RNA transcribed. Complimentary to sense strand - the coding strand

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

Describe the basic structure of transcription.

A
  1. DNA unwinds
  2. Ribonucleotides base pair with the antisense DNA template
  3. RNA Polymerase creates phosphodiester bonds between Ribonucleotides in the 5’ to 3’ direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two types of transcription factors?

A

Transcriptional activators: upregulation

Transcriptional repressors: downregulation

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

What is the initiation step

A

The construction of a transcription complex at the gene promotor before transcription can begin

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

What is the specific DNA sequence that marks the point of initiation for RNA Pol II

A

TATA

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

What is the basal transcription complex? (BTC)

A

The complex that produces a low level of transcription in the absence of other factors

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

What is the effect of the basal transcription complex on RNA Pol?

A

Alloes RNA Pol II to be phosphorylated and commence transcription

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

What is the first step of formation of the BTC

A 
TF IID (TATA binding protein) binds to TATA.
Partially unravels DNA, and widens minor groove for increased base contact.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is unidirectional transcription achieved.

A

DNA is unwound asymmetrically.

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

What is the second step of the BTC formation?

A

TF IIA and IIB bind to IID.

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

What does TF IIB do?

A

Binds to RNA Pol II and TF IID

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

Which other Transcription factors bind to RNA Pol II?

A

TF IIF, IIE, IIH, IIJ

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

What do TF’s actually do?

A

Bend DNA on binding making transcription possible/easier.

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

Name the letters of all the TF II’s involved in the BTC

A

D,A,B, F,E,H,J

“Dab Jehf, Dab!”

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

What do transcription factors also do to change the expression of genes?

A

Modify chromatin by recruiting proteins with enzymatic activity that modify histones

20
Q

How do TF modify histones?

A

Hyperacetylation: DNA exposed, gene expressed
Hypoacetylation: DNA hidden, gene repressed

21
Q

What do mutated/abnormal TFs lead to?

A

Cancer

22
Q

Which factors effect Transcription factor expression?

A

Cell lineage

External signals: Hormones, growth factors, mechanical stress

23
Q

What is the primary transcript known as?

A

pre-mRNA
or
Heterogenous nuclear RNA (hnRNA)

24
Q

How are eukaryotic genes coded in DNA?

A

Discontinuously in Exons w/introns in between

25
Q

How is the primary transcript processed, and where?

A

Introns are cleaved out in the nucleus.

26
Q

What is the name of the location where the end of an exon is cleaved from the intron?

A

Splice donor site

last 2 bases of exon and GU of intron

27
Q

What is the name of the location where the end of an intron is cleaved from an exon?

A

Splice acceptor site

15 pyrimidine bases, any base then CAG (Pyr15NCAG)

28
Q

Which bases mark the end of introns and exons?

A

AG

29
Q

Which bases mark the beginning of an intron?

A

GU

30
Q

What does mRNA processing require?

A

snRNP’s

Small ribonuclear proteins

31
Q

Which snRNP binds to the splice donor site?

A

U1

32
Q

Which snRNP binds to the splice acceptor site?

A

U5

33
Q

Which snRNPs bind to the middle of the intron?

A

U2, U4, U6

34
Q

What is the name of the complex that forms from binding of snRNPs?

A

Spliceosome

35
Q

What does U1 do?

A

Cleaves splice donor site

36
Q

What happens to the GU at the beginning of spliced intron?

A

Forms phosphodiester bond with branchpoint in the middle of intron

37
Q

What does U5 do?

A

Cleaves splice acceptor site

38
Q

What is the stucture of the cleaved intron called?

A

Lariat structure

39
Q

What happens to the cleaved intron?

A

It is destroyed

40
Q

What happens to two adjacent exons of mRNA?

A

They are ligated by RNA Ligase into a continuous sequence

41
Q

What are the Post-transcriptional modifications of mRNA?

A

5’ Capping

3’ Poly-A tail

42
Q

What happens in 5’ capping?

A

A phosphate is removed from the 5’ end of mRNA.
This is joined to GMP forming a 5’-5’ phosphate linkage.
The 7’ carbon in guanine is methylated.
7-methylguanylate cap

43
Q

What is the function of a 5’ cap?

A

To protect the mRNA from exonuclease activity.

Allow recognition by ribosomes and increased translation.

44
Q

What virus causes removal of caps preventing protein synthesis in infected cells?

A

Polio

45
Q

How long is the Poly-A tail?

A

10-200 bases

46
Q

What is the function of the Poly-A tail?

A

To stabilise the mRNA

A’s removed after translation, to monitor age of mRNA, and prevent translation of damaged mRNA

*MCD NAGE Y1* (7 decks)

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