Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A BIO105 - GENETICS > Gene Regulation > Flashcards

Gene Regulation 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
Who first proposed the theory of Operon?
- Francis Jacob - Jacques Monod
26
A cluster of genes encoding related enzymes that are regulated together
Operon
27
What is an Operon?
A cluster of genes encoding related enzymes that are regulated together
28
Two Categories of Gene Control
- Negative Regulation - Positive Regulation
29
What is a Negative regulation?
A process of regulating gene expression by inhibiting the expression of that specific gene
30
What is present in the cell in Negative regulation?
an inhibitor (repressor) that keeps transcription turned off
31
What is called for an anti-inhibitor?
Inducer
32
What is inducer for?
needed to turn the system on
33
Example of Negative Regulation
Lactose operon
34
What is a Positive regulation?
Initiates the transcription process on the presence of proteins
35
An effector molecule
- protein - small molecule - molecular complex activates a promoter
36
Example of Positive regulation
Lactose operon (cAMP-crp)
37
Two Types of Regulatory Proteins
- Repressors - Activators
38
What is a Repressors?
Repress an operon by binding to operator physically
39
Repressors prevent ____ ____
mRNA synthesis
40
How can repressors prevent mRNA synthesis?
By denying RNA polymerase access to the promoter
41
Repressors can combine with ____
effectors
42
What is Activators?
bind to activator sites at near promoters
43
Activators ______ _____ with which RNA polymerase binds to promoter
increase efficiency
44
Example of Activators
- ara C protein - cAMP-crp
45
Two Types of Effectors
- Inducers - Corepressors
46
What are Inducers for?
Combine with repressors to decrease their binding affinity to DNA
47
Example of Inducers
Allolactose in lactose operon
48
What are Corepressors for?
Combine with repressors making them functional
49
Example of Corepressors
Tryptophan
50
Two Types of Proteins in Bacterial Cells
- Structural proteins - Regulatory proteins
51
Structural proteins
do not regulate transcriptio
52
Example of Structural proteins
- enzymes - membrane proteins - ribosomal components
53
Regulatory proteins
- help sense environment - regulate rate of transcription of structural genes by binding to DNA
54
Genes that are actively transcribed (and translated) under all experimental conditions, at essentially all developmental stages, or in virtually all cells
Constitutively expressed genes
55
Genes that are transcribed and translated at higher levels in response to an inducing factor
Inducible genes
56
Genes whose transcription and translation decreases in response to a repressing signal
Repressible genes
57
- genes for enzymes of central metabolic pathways (e.g. TCA cycle) - these genes are constitutively expressed - the level of gene expression may vary
Housekeeping genes
58
Gene regulation is well studied in ___
E. coli
59
What will happen if a bacterial cell encounter a potential food source?
It will manufacture the necessary enzyme to metabolize that food
60
What did Monod and Jacob examined in 1959?
The ability of E. coli cells to digest the sugar lactose
61
In the presence of the sugar lactose, what enzyme is manufactured?
E. coli makes an enzyme called beta galactosidase
62
How can the E. coli makes the enzyme called beta galactosidase?
when the sugar lactose is present
63
What enzyme breaks down the sugar lactose?
Beta galactosidase
64
Why must the beta galactosidase breaks down the sugar lactose?
so that the E. coli can digest it for food
65
What gene in E. coli that codes for the enzyme beta galactosidase?
LAC Z gene
66
What is the LAC Z gene?
It codes for the enzyme beta galactosidase
67
E. coli bacteria only needs beta galactosidase, if what?
If there is lactose in the environment to digest
68
lac operon
TTTACA / TATGTT
69
What is lac operon?
- weak promoter - has a basal expression level
70
CRP
cAMP receptor protein
71
Binding site of CRP
at -60 region
72
What is CRP?
a homodimer with binding ability to DNA and cAMP
73
It is an example of positive control
Catabolite Repression
74
What is Catabolite Repression?
Repression of some sugar-metabolizing operons in favor of glucose utilization
75
Catabolite Repression is manifested by what operons?
maltose, sorbitol, lactose, arabinose, galactose
76
What is needed in Catabolite repression to turn on the operons?
cAMP
77
Glucose reduces level of cAMP by _____
inactivating adenylate cyclase
78
High glucose =
low cAMP
79
one of the constitutive genes expressed at the basal level
trp operon (tryptophan)
80
For eukaryotic systems: It is the special DNA sequence that can affect the expression of its own gene
Cis-acting elements
81
For eukaryotic systems: The regulatory proteins
transcription factors (TF)
82
A term reffered to TF after it interact with the cis-acting elements to activate another genes
trans-acting factors
83
Control of gene expression in eukaryotic cells occurs at which level(s)?
- epigenetic - transcriptional - post-transcriptional - translational - post-translational levels
84
Genes within an operon:
- are generally involved in the same biochemical pathway - are expressed as a polycistronic RNA - tend to be regulated by a common regulatory mechanism
85
If glucose is absent, but so is lactose, the lac operon will be ________
repressed
86
Post-translational control refers to:
regulation of gene expression after translation
87
Post-translational modifications of proteins can affect which of the following?
protein function
88
Prokaryotic cells lack a nucleus. Therefore, the genes in prokaryotic cells are:
transcribed and translated almost simultaneously AND transcriptionally controlled
89
The binding of ________ is required for transcription to start
RNA polymerase
90
What will result from the binding of a transcription factor to an enhancer region?
increased transcription of a distant gene
91
Which of the following are involved in post-transcriptional control?
- control of RNA shuttling - control of RNA stability - control of RNA splicing
92
Which of the following would you expect to find in an inducible system?
A repressor protein, which is bound to DNA in absence of any other factor

A BIO105 - GENETICS (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions