BIO3: Control of Gene Expression: Biotechnology Flashcards

1
Q

 polycistronic

A

Polycistronic mRNA can encode more than one polypeptide separately within the same RNA molecule (e.g. bacteria)

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2
Q

Describe monocistronic

A

Monocistronic mRNA (primarily in eukaryotes) contain the coding sequence only for one polypeptide

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3
Q

How do prokaryotes control gene expression?

A

Operons that result in multiple genes per mRNA (polycistronic mRNA) only exist in prokaryotes

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4
Q

operons

A

Operons are a group of genes controled by a single promoter (all or nothing expression)

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5
Q

How do eukaryotes control gene expression?

A
  1. Transcription regulation
  2. Changes in gene number
  3. Translation regulation
  4. Failure to control
  5. DNA and chromatin structural modifications
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6
Q

operator

A

Operators are regions of DNA which enables the regulation of genes on the operon

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7
Q

What type of proteins bind regulate transcriptional activity in prokaryotes?

A

Activator and repressor proteins (decrease rate of transcription)

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8
Q

Describe the lac operon

A

Lac operon plays a catabolic role where transcription of lac is induced by the presence of lac (the substrate) that the operon’s enzymes break down

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9
Q

Describe the trp operon

A

Trp operon play an anabolic role where transcription of trp is represssed by the presence of trp (the product) of the operon’s enzymes

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10
Q

What are the components of the Lac Operon?

A
  1. Promoter region (P region) - RNA pol binds to begin transcription
  2. Operator region (O region) - repressor binds to decrease transcription
  3. Structural genes - lac Z, lac Y, lac A
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11
Q

How is gene expression controlled in bacteria?

A

In prokaryotes, gene regulation occurs at the transcription level (since transcription and translation occur simultaneously); the stronger the affinity between RNA pol and the promoter, the higher the transcription rate

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12
Q

Where does regulation of gene expression occur in bacteria?

A

Repressor proteins bind to the operator region of DNA; activator proteins bind to the enhancer region of DNA

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13
Q

transcription factor (TF)

A

TFs are proteins that control the rate of transcription by activating/repressing the activity of RNA Pol and modulate the interaction of RNA Pol and the promoter

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14
Q

RNA processing

A

The addition of a 5’ cap and 3’ poly-A tail that increases the stability of RNA, making it last longer in the cytosol

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15
Q

How many times can RNA be translated?

A

mRNA can continuous be read to make proteins

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16
Q

RNA interference

A

RNA molecules reduce translation by degrading some specific mRNA molecules

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17
Q

What types of RNA are involved in RNA interference?

A
  1. miRNA

2. siRNA

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18
Q

miRNA

A

miRNA are single stranded RNA molecules that are complementary to the mRNA molecule, bind to it, and degrade it

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19
Q

siRNA

A

siRNA are double stranded RNA that forms a complex with a protein, binds to a specific mRNA molecule, cleiving it

20
Q

gene amplification

A

Gene amplification (or gene duplication) is the duplication of a region of DNA resulting in an increase in the number of copies of a gene

21
Q

anueploidy

A

Having an abnormal # of chromosomes (an entire chromosome has been duplicated or lost)

22
Q

angiogenesis

A

Development of new blood vessels

23
Q

Describe the cancer growth process

A

Normal cells undergo apoptosis when DNA mutations occur but cancer cells avoid apoptosis. Cancer cells undergo angiogenesis which fuels tumor groups. Cancerous tissue invades and damages surrounding organs

24
Q

oncogenes

A

Genes that regulate cell growth, differentiation, and the process of apoptosis and can potentially cause cells to become cancerous

25
Q

proto-oncogenes

A

Normal genes involved in cell growth that get mutated

26
Q

tumor suppressor genes

A

Genes that have the potential to prevent cancer (trigger apoptosis, DNA repair, or decrease cell division)

27
Q

epigenetics

A

Changes in gene expression not due to change in DNA sequence (e.g. chromatin remodeling)

28
Q

chromatin remodeling

A

Changing arrangement of chromatin between heterochromatin/euchromatin that leads to changes in gene expression

29
Q

What types of covalent modifications occur to histone proteins in chromatin remodeling?

A
  1. Acetylation/deacetylation
  2. Methylation/demethylation
  3. Phosphorylation
30
Q

rDNA

A

Recombinant DNA are DNA molecules made from combining DNA from 2 or more different sources

31
Q

restriction enzymes

A

endonucleases that recognize and cleave specific DNA sequences (producing “sticky ends” and rDNA when annealed)

32
Q

endonuclease

A

enzyme that cleaves a nucleotide chain in the middle of the chain

33
Q

exonuclease

A

enzyme that cleaves a nuscleoide from the end of a chain

34
Q

phosphodiester bonds

A

joins nucleotides

35
Q

FISH

A

Flourescent in situ hybridization - used to determine gene expression in a specific tissue

36
Q

What questions does FISH address?

A

Is a certain gene expressed? If so, how much and in what region of tissue?

37
Q

PCR

A

Polymerase chain reaction - used to amplify DNA to determine quantity of DNA present

38
Q

Describe the PCR process

A

Repeated cycles of heating and cooling (denature and anneal) and DNA extension

39
Q

Gel eletrophoresis

A

Used to separate macromoles of DNA and proteins by size and charge

40
Q

Describe the gel eletrophoresis process

A

Sample is placed at - (cathode) end of gel and electrical field is applied so negatively charged molecules migrate towards + (anode) opposite end of gel

41
Q

SDS-PAGE

A

Separate denatured proteins by their molecular weight

42
Q

Native-PAGE

A

Proteins separated by size in their native conformation

43
Q

Southern blot

A

Detect a certain fragment of DNA from a sample

44
Q

Northern blot

A

Detect a certain fragment of RNA from a sample

45
Q

Western blot

A

Detect a specific protein from sample

46
Q

Sanger sequencing

A

Method of DNA sequencing using ddNTP to terminate nucleotide chain elongation and generate various fragments to map to