Gene Expression and Biotech (complete) Flashcards Preview

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Flashcards in Gene Expression and Biotech (complete) Deck (91)
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1

where are the two levels where regulation of gene expression can occur

1. Transcription
2. Translation

2

What is the difference between cis-acting and trans-acting regulation

cis-acting regulation is transcriptional regulation based on the DNA sequence alone
trans-acting regulation is transcriptional regulation based on something outside of the DNA sequence

3

Trans-acting regulation factors are usually _______

proteins which bind to the DNA

4

do trans anc cis-acting regulation factors usually work together? if so how?

trans-acting regulation factors usually bind to the cis-acting factors

5

Of these, which are cis-acting
1. RNA polymerase
2. Helicase
3. Transcription factors
4. promoter
5. gene
6. enhancer
7. repressor

Promotor
Gene
Enhancer
repressor

6

Of these, which are trans-acting
1. RNA polymerase
2. Helicase
3. Transcription factors
4. promoter
5. gene
6. enhancer
7. repressor

RNA polymerase
Helicase
Transcription factors

7

Is most regulation of gene expression done at translation or transcription

transcription

8

Where is gene expression regulation done in prokaryotes

only transcription, no translation

9

What is an operon

a cluster of genes with related functions, acting as a coordinated unit and controlled by a regulatory sequence

10

What are the components of an operon

1. Structural genes
2. Promoter
3. Repressor
4. Activator
5. Operator

11

What are the structural genes of an operon

the genes that code for proteins

12

what is the difference between the structural genes of an operon in prokaryotes vs. eukaryotes

the structural genes in eukaryotes only codes for one protein, where as in prokaryotes it can code for multiple proteins

13

Is operon usually used in association with prokaryotes or eukaryotes

prokaryotes

14

What is the promoter of an operon

1. it is the location where the RNA polymerase will bind
2. It has the TATA box
3. it increases the efficiency of gene transcription

15

What is the repressor of an operon

1. a gene that codes for an inhibitor protein of the gene
2. it inhibits the transcription of the protein

16

What is an activator of an operon

1. it increase the transcription of a protein
2. a gene that codes for an activator protein of the gene

17

What is an operator of an operon

the sequence of DNA that binds repressor or activator proteins

18

How many promoters per gene is there in eukaryotes

one promoter per gene

19

How many promoters per gene are there in prokaryotes

multiple promoters per gene

20

Genes can be either:
1. Constantly activated and turned off when you have too much of the protein
2. Constantly inactivated and turned on when more of the protein is needed
True or False? if only one, which is it?

True,

21

In prokaryote transcription, what is the concensus sequence

1. the preferred binding sequence for transctiption factors.
2. it is about 35 bases prior to the location where transcription begins
3. TTGACA is the sequence

22

in prokaryote transcription, what is the pribnow box

a portion of the promoter that is about 10 bases prior to transcription start point
TATAAT is the sequence

23

What are the proteins that are a created and regulated by the LAC operon

They are three catabolic enzymes that break down lactose

24

Which prokaryotic operon is known as the catabolic operon

the LAC operon

25

Is the Lac operon normally on, or off

the lac operon is normally OFF

26

When is the lac operon turned on

when lactose needs to be used for energy
(When there is high lactose and allolactose)

27

What is the lac operon like in its normal state

1. It is off
2. it has a repressor protein (from the repressor gene)that is bound to its operator

28

How does the lac operon get turned on

1. Lactose enters the scene and binds to the repressor protein that is on the operon, this pulls the repressor protein off and allows transcription to begin

29

What is an inducer

a substance that binds to a repressor, causing it to be inactive

30

in the LAC operon what is the inducer

lactose