Brainscape's Knowledge GenomeTM

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


See full index

BIO 1A03 > T3- M3&4 > Flashcards

T3- M3&4 Flashcards

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

What did all cells derive from

A

Fertilized eggs

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

What determines a cell’s fate

A

Which genes are turned on/off

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

Why are signals important

A

To control gene expression

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

Define proteome

A

The complete set of proteins made by an organism

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

What are transcription factors

A

Proteins which bind to specific DNA sequences

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

Why are transcription factors essential

A
  • Determine pathway for cell type
  • Work with other proteins that result in gene expression changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are transcriptional regulation in prokaryotes and eukaryotes similar

A
  • Both activate and repress transcription
  • both use RNA polymerase to bind to promotors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How are the DNA in eukaryotes and why

A

Highly compact chromatin- easy way to fit DNA in nucleus

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

What do chromatin do

A

Allow DNA to move around in cell divison

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

Are genes in tight chromatin expressed?

A

No, need to unwind

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

What is DNA wrapped around

A

Histone proteins

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

How many histone proteins does each nucleosome have

A

8 with 150 base pairs

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

What is chromatin remodelling

A

The rearrangement of chromatin from a condensed state to a transcriptionally accessible state

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

What is needed for chromatin remodelling

A

Activator protein or transcription factor

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

How is DNA tightly bound

A

Due to positive tails of histones and negatively charged phosphate in DNA

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

What is the activator protein recruited for histone modifications

A

Coactivator enzyme histone acetyltransferase

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

What does coactivator enzyme histone acetyltransferase do

A

Attaches acetyl groups to lysine amino acids along positive tails of nucleosome histone proteins

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

What happens once positive tails are acetylated

A

Positive charge is reduced and interactions between histones and DNA reduced

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

What other modifications assist in transcription initiation

A

Methylation of lysine and arginine
Phosphorylaton of serine and theanine

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

4 types of transcription factor proteins

A
  • include basic helix loop helix
  • helix turn helix
  • zinc finger
  • leucine zipper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What bonds are between alpha helical domains

A

Hydrogen bonds

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

What is the promotor sequence in eukaryotes

A

TATA box

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

What is a core promotor

A

A binding site for RNA polymerase and other transcription factors

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

What is recognized by TATA box

A

TATA binding protein or TBP subunit of transcription factor TF2D

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

What is the BRE region

A

Promoter for eukaryotes

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

What is BRE region bound by

A

TF2B factor

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

What are enhancer regions

A

Bind cell or region specific transcription factors
- facilitates formation of transcriptional complex

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

Where are enhancer sequences in eukaryotes

A

Distant from promotor

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

What happens once transcriptional components bound

A

Flexible DNA allows factors and RNA poly to loop

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

What do adaptor or mediator proteins do

A

Connect enhancer proteins to promotor proteins

31
Q

What are silencer proteins

A

Bind transcriptional repressors to halt transcription
- positioned upstream of target gene

32
Q

What does silencer region activation cause

A

Interference of general transcription factor assembly and mediator activity

33
Q

What type of cells specialize to hemoglobin

A

Blood cell progenitors/ stem cells

34
Q

What must happen before progenitor cells differentiate into red blood cells

A

Transcription of globin proteins

35
Q

What hemoglobin proteins are in both fetus and adults

A

2 alpha globin proteins

36
Q

What hemoglobin protein is unique to fetus

A

2 gamma globin proteins

37
Q

What hemoglobin proteins are unique to adults

A

2 beta globin proteins

38
Q

Why do fetuses need gamma globin proteins

A

Gamma globin proteins bind more oxygen, allowing the fetus to use it for development in womb

39
Q

What does chromatin of beta globin gene do in fetus

A

It is tightly wrapped to prevent transcription

40
Q

What does chromatin of beta globin gene do in adult

A

It is loose to allow transcription

41
Q

What does methylation of nucleotide bases do

A

Inhibit transcription

42
Q

What is the most common nucleotide modification in DNA

A

Addition of methyl group to cytosine base

43
Q

What are CpG islands

A

A string of cytosine and guanine bases where methyl group is added

44
Q

What does p represent in CpG islands

A

Phosphate group

45
Q

Where are CpG islands located

A

Near promotors

46
Q

What happens when CpG islands not methylated?

A

DNA binding proteins recognize promotor and transcription occurs

47
Q

What happens when CpG islands methylated?

A

Shape of DNA binding site is changed and protein cannot bind- no transcription

48
Q

Define HDAC

A

Histone Deacetylases
- Bind to DNA and promote removal of acetyl group from neighboring proteins

49
Q

What is the purpose of HDAC proteins

A

Allow nucleosomes to reassemble and mask enhancer and promotor sequences
* repress transcription

50
Q

What is the default nature of chromatin in prokaryotes

A

Default “off”

51
Q

What is the default nature of chromatin in eukaryotes

A

Default chromatin “on”

52
Q

What does amount of gene product vary upon

A
  • changing conditions
  • different signals
53
Q

Where can gene expression be regulated

A
  • transcription/ initiation
  • RNA processing
  • stability of RNA
  • Protein synthesis
  • Protein modification/ transport
  • Protein degregation
54
Q

Describe In Situ Hybridization

A

Lab technique used to identify which cells and tissues express gene by undertaking analysis of finding mRNA in organism development

55
Q

How was mRNA detected

A

Complimentary probe with tag

56
Q

What does complimentary probe have

A

Fluorescently labelled short, single stranded segment of DNA/RNA which binds complimentary to mRNA

57
Q

Describe DNA microarray

A

Lab technique where glass slides with known DNA act as probes to detect gene expression in a pattern

58
Q

What can microarrays show

A

Thousands of genes at once and help visualize variation in gene expression in different cell types

59
Q

What must happen to mRNA to be labelled

A

Isolated from cell

60
Q

What needs to be made as a template for mRNA

A

Complementary cDNA molecules using reverse transcriptase enzyme
- florescent nucleotides used and become part of new cDNA molecule

61
Q

Describe how mRNA from normal and epithelial cells were combined in hybridization

A

Equal amounts were placed with normal being green and cancer being red

62
Q

How to know if gene is active

A

Produces a lot of mRNA and lots of cDNA- BRIGHT SPOT

63
Q

What did it mean if the spot was green?

A

Specific gene is expressed more in normal cells

64
Q

What did yellow spots mean

A

Gene equally expressed in both

65
Q

What does no brightness mean?

A

Gene not expressed

66
Q

What must happen to mRNA to stop gene expression

A

Must be degraded

67
Q

How was poly a tail affect mRNA

A

Needed for stability

68
Q

Describe miRNA

A

short, non coding regulatory double stranded molecules which to become part of the silencing complex

69
Q

What does miRNA form

A

Hairpin loops due to complimentary base pairing

70
Q

What do the miRNA hairpin loops do

A

Process into single stranded mRNA fragments which activate RNA interference machinery

71
Q

What do miRNA and RISC complex do

A

Bind to target mRNA sequence for translation miRNA

72
Q

What is siRNA

A

Small interfering RNA which is associated with RISC complex
- exact compliments of mRNA target

73
Q

Purpose of proteasomes

A

Degrade unneeded or damaged proteins by marking them

BIO 1A03 (10 decks)

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