Gene Regulation Flashcards

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

In eukaryotes, how many polypeptide chain can be translated from a processed mRNA molecule?

A

Only a single polypeptide chain

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

Regulatory sites for transcription in prokaryotes?

A
  • promoters
  • operators and regulators are small
  • near to and usually upstream from start point
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Regulatory regions in eukaryotes

A
  • much larger
  • hundreds of bases away
  • no operons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A large fraction of the base sequences in eukaryotic mRNA is ________

A

untranslated

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

It is present in eukaryotic genes

A

Introns

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

Spliced in eukaryotes

A

eukaryotic mRNA

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

In eukaryotes, it is synthsized

A

RNA

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

In eukaryotes, RNA is synthesized where?

A

nucleus

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

Where does the synthesized RNA in the nucleus must be transported?

A

transported throught the nuclear membrane to the cytoplasm where it is translated

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

After the synthesized RNA is transported to the nuclear membrane, it is translated in?

A

Cytoplasm

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

In prokaryotes, there is no _____ _____

A

nuclear membrane

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

In prokaryotes translation of ______ ____ can occur even before transcription has been completed

A

nascent mRNA

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

There is _____ _____ and more _____ ____ of gene regulation in eukaryotes than in prokaryotes

A
  • great number
  • more complex levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is gene expression?

A

A biological processes that yield a gene product

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

It is expressed when its biological product is present and active

A

Gene

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

When is gene expressed?

A

When its biological product is present and active

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

Gene expression is regulated at ______ levels

A

multiple levels

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

Each cell in your body expresses only a _____ ____ of genes at any time

A

small subset

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

During development, what cells expresses sets of genes?

A

different cells expresses different sets of genes

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

Gene regulation is express in what way?

A

A precisely regulated fashion

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

What level does gene regulation occurs?

A
  • transcription
  • production of mRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A given cell transcribes what

A

only a specific set of genes and not others

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

Gene products should be what?

A

released at the right time, in the right place and in the right amounts

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

Gene regulation in prokaryotes is mainly for?

A
  • growth
  • response to environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Who first proposed the theory of Operon?

A
  • Francis Jacob
  • Jacques Monod
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

A cluster of genes encoding related enzymes that are regulated together

A

Operon

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

What is an Operon?

A

A cluster of genes encoding related enzymes that are regulated together

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

Two Categories of Gene Control

A
  • Negative Regulation
  • Positive Regulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is a Negative regulation?

A

A process of regulating gene expression by inhibiting the expression of that specific gene

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

What is present in the cell in Negative regulation?

A

an inhibitor (repressor) that keeps transcription turned off

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

What is called for an anti-inhibitor?

A

Inducer

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

What is inducer for?

A

needed to turn the system on

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

Example of Negative Regulation

A

Lactose operon

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

What is a Positive regulation?

A

Initiates the transcription process on the presence of proteins

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

An effector molecule

A
  • protein
  • small molecule
  • molecular complex activates a promoter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Example of Positive regulation

A

Lactose operon (cAMP-crp)

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

Two Types of Regulatory Proteins

A
  • Repressors
  • Activators
38
Q

What is a Repressors?

A

Repress an operon by binding to operator physically

39
Q

Repressors prevent ____ ____

A

mRNA synthesis

40
Q

How can repressors prevent mRNA synthesis?

A

By denying RNA polymerase access to the promoter

41
Q

Repressors can combine with ____

A

effectors

42
Q

What is Activators?

A

bind to activator sites at near promoters

43
Q

Activators ______ _____ with which RNA polymerase binds to promoter

A

increase efficiency

44
Q

Example of Activators

A
  • ara C protein
  • cAMP-crp
45
Q

Two Types of Effectors

A
  • Inducers
  • Corepressors
46
Q

What are Inducers for?

A

Combine with repressors to decrease their binding affinity to DNA

47
Q

Example of Inducers

A

Allolactose in lactose operon

48
Q

What are Corepressors for?

A

Combine with repressors making them functional

49
Q

Example of Corepressors

A

Tryptophan

50
Q

Two Types of Proteins in Bacterial Cells

A
  • Structural proteins
  • Regulatory proteins
51
Q

Structural proteins

A

do not regulate transcriptio

52
Q

Example of Structural proteins

A
  • enzymes
  • membrane proteins
  • ribosomal components
53
Q

Regulatory proteins

A
  • help sense environment
  • regulate rate of transcription of structural genes by binding to DNA
54
Q

Genes that are actively transcribed (and translated) under all experimental conditions, at essentially all developmental stages, or in virtually all cells

A

Constitutively expressed genes

55
Q

Genes that are transcribed and translated at higher levels in response to an inducing factor

A

Inducible genes

56
Q

Genes whose transcription and translation decreases in response to a repressing signal

A

Repressible genes

57
Q
  • genes for enzymes of central metabolic pathways (e.g. TCA cycle)
  • these genes are constitutively expressed
  • the level of gene expression may vary
A

Housekeeping genes

58
Q

Gene regulation is well studied in ___

A

E. coli

59
Q

What will happen if a bacterial cell encounter a potential food source?

A

It will manufacture the necessary enzyme to metabolize that food

60
Q

What did Monod and Jacob examined in 1959?

A

The ability of E. coli cells to digest the sugar lactose

61
Q

In the presence of the sugar lactose, what enzyme is manufactured?

A

E. coli makes an enzyme called beta galactosidase

62
Q

How can the E. coli makes the enzyme called beta galactosidase?

A

when the sugar lactose is present

63
Q

What enzyme breaks down the sugar lactose?

A

Beta galactosidase

64
Q

Why must the beta galactosidase breaks down the sugar lactose?

A

so that the E. coli can digest it for food

65
Q

What gene in E. coli that codes for the enzyme beta galactosidase?

A

LAC Z gene

66
Q

What is the LAC Z gene?

A

It codes for the enzyme beta galactosidase

67
Q

E. coli bacteria only needs beta galactosidase, if what?

A

If there is lactose in the environment to digest

68
Q

lac operon

A

TTTACA / TATGTT

69
Q

What is lac operon?

A
  • weak promoter
  • has a basal expression level
70
Q

CRP

A

cAMP receptor protein

71
Q

Binding site of CRP

A

at -60 region

72
Q

What is CRP?

A

a homodimer with binding ability to DNA and cAMP

73
Q

It is an example of positive control

A

Catabolite Repression

74
Q

What is Catabolite Repression?

A

Repression of some sugar-metabolizing operons in favor of glucose utilization

75
Q

Catabolite Repression is manifested by what operons?

A

maltose, sorbitol, lactose, arabinose, galactose

76
Q

What is needed in Catabolite repression to turn on the operons?

A

cAMP

77
Q

Glucose reduces level of cAMP by _____

A

inactivating adenylate cyclase

78
Q

High glucose =

A

low cAMP

79
Q

one of the constitutive genes
expressed at the basal level

A

trp operon (tryptophan)

80
Q

For eukaryotic systems:
It is the special DNA sequence that can affect the expression of its own gene

A

Cis-acting elements

81
Q

For eukaryotic systems:
The regulatory proteins

A

transcription factors (TF)

82
Q

A term reffered to TF after it interact with the cis-acting elements to activate another genes

A

trans-acting factors

83
Q

Control of gene expression in eukaryotic cells occurs at which level(s)?

A
  • epigenetic
  • transcriptional
  • post-transcriptional
  • translational
  • post-translational levels
84
Q

Genes within an operon:

A
  • are generally involved in the same biochemical pathway
  • are expressed as a polycistronic RNA
  • tend to be regulated by a common regulatory mechanism
85
Q

If glucose is absent, but so is lactose, the lac operon will be ________

A

repressed

86
Q

Post-translational control refers to:

A

regulation of gene expression after translation

87
Q

Post-translational modifications of proteins can affect which of the following?

A

protein function

88
Q

Prokaryotic cells lack a nucleus. Therefore, the genes in prokaryotic cells are:

A

transcribed and translated almost simultaneously AND transcriptionally controlled

89
Q

The binding of ________ is required for transcription to start

A

RNA polymerase

90
Q

What will result from the binding of a transcription factor to an enhancer region?

A

increased transcription of a distant gene

91
Q

Which of the following are involved in post-transcriptional control?

A
  • control of RNA shuttling
  • control of RNA stability
  • control of RNA splicing
92
Q

Which of the following would you expect to find in an inducible system?

A

A repressor protein, which is bound to DNA in absence of any other factor