2.4 Control of gene expression

Question 1

What is critical for all organisms?

Answer 1

Regulation of gene expression

Question 2

What are three important things for the regulation of gene expression?

Answer 2

Genes and regulatory elements. Levels of gene regulation. DNA-Binding Proteins

Question 3

What are operons?

Answer 3

In bacteria, groups of genes that are transcribed as a unit

Question 4

What are structural genes?

Answer 4

Enconding proteins that are not regulatory

Question 5

What are two examples of strucutural genes?

Answer 5

Tubulin and enzymes

Question 6

What are regulatory genes?

Answer 6

Encoding products that interact with other sequences and affect the transcription and translation of these sequences

Question 7

What is an example of regulatory genes?

Answer 7

Transcription Factors

Question 8

What are regulatory elements?

Answer 8

DNA sequences that are not transcribed but play a role in regulating other nucleotide sequences.

Question 9

What is an ex of regulatory elements?

Answer 9

Promoter sequence

Question 10

What is constitutive expression?*

Answer 10

Genes is always on.

Question 11

What is positive control?

Answer 11

Turn on gene expression

Question 12

What is negative control?

Answer 12

Turn off gene expression

Question 13

Where does transcription begin?

Answer 13

the initial transcription binding site, not the start codon

Question 14

Why does the splicesome have to be nearly perfect?

Answer 14

Because the message will be trash if its not

Question 15

What are domains?

Answer 15

group of AA responsible for binding to DNA forming hydrogen bonds with DNA

Question 16

What is a motif?

Answer 16

Within the binding domain, simple structure that fits into the major groove of the DNA

Question 17

What are three types of DNA binding proteins?

Answer 17

Helix-turn-helix, zinc fingers, leucine zipper

Question 18

How are DNA-binding proteins grouped?

Answer 18

On structures or motifs

Question 19

What is the structure of an operon?

Answer 19

promoter+operator+structural genes

Question 20

What is a promoter?

Answer 20

region of DNA that initiated transcription of a particular gene

Question 21

What helped produce the large phenotypic differences between humans and chimps?

Answer 21

Changes in small number of regulatory sequences

Question 22

How do euk and bac differ pertaining to gene regulation? 3 ways

Answer 22

In euk: 1. Each structural gene has its own promoter and is transcribed separately. 2. DNA must unwind from the histone proteins before transcription. 3. Transcription and translation are separated in time and space.

Question 23

What is the significance of DNase I hypersensitivity?

Answer 23

These sites have a more open chromatin configuration site. Include promoters, enhancers, insulators, silencers and locus control regions.

Question 24

What are two ways for histone modification?

Answer 24

Addition of methyl groups to histone tails and addition of acetyl groups to histone proteins

Question 25

What do chromatin remodeling complexes do?

Answer 25

reposition the nucleosomes, bind to DNA sites and unwind.

Question 26

What happens when histone proteins are acetylated?

Answer 26

Their charge is altered, allowing transcription factors to bind to DNA. Activating genes.

Question 27

Where does DNA methylation occur?

Answer 27

In the CpG islands.

Question 28

whats the difference between active genes and unactive genes?

Answer 28

The Active genes will have the Cs unmethylated. The unactive genes will have the Cs methylated.

Question 29

What is ChlP?

Answer 29

Tool used to study DNA binding proteins or events. By using antibodies that bind to specific proteins.

Question 30

What is the initiation of transcription regulated by?

Answer 30

Transcription factors and regulator proteins

Question 31

What do transcriptional activators and coactivators do?

Answer 31

Stimulate and stabilize basal transcription apparatus at core promoter

Question 32

What is the main function of mediator complexes?

Answer 32

Transmit signals from the transcription factors to the polymerase

Question 33

What do enhancers do?

Answer 33

Improve efficiency of transcription

Question 34

How do euk's solve the problem of activating different genes that need to work together?

Answer 34

Take transcription recognition sites and swap them out around the genes that need to work together.

Question 35

What do insulators do?

Answer 35

Blocks the effect of enhancers

Question 36

What do transcriptional repressors do?

Answer 36

Bind to silencers

Question 37

How are genes able to respond to multiple inducers (multiple response elements)?

Answer 37

By having complicated promoters.

Question 38

What are heat shock proteins?

Answer 38

produced by cells in response to exposure to stressful conditions.

Question 39

What happens if there is no environmental stress?

Answer 39

Transcription stalls near start codon

Question 40

What is an example of coordinated gene regulation?

Answer 40

Steroid response elements

Question 41

What are response elements?

Answer 41

Common regulatory elements upstream of the start sites of a collective group of genes in response to a common environmental stimulus.

Question 42

What are two examples of gene regulation through RNA splicing?

Answer 42

splicing in the T-antigen gene and splicing in the Drosophila sexual development.

Question 43

What occurs in every category of cancer hallmarks?

Answer 43

Alternative splicing

Question 44

What are two RNAs used in RNA interference?

Answer 44

siRNAs and microRNAs

Question 45

What are the components to siRNAs and microRNAs?

Answer 45

Dicer and RISC (RNA-induced silencing complex).

Question 46

What does microRNAs do?

Answer 46

Turn off genes.

Question 47

What does MiR-1 do?

Answer 47

Plays a role in shutting down genes in proliferation

Question 48

What does RNA silencing lead to?

Answer 48

Degradation of mRNA or to the inhibition of translation or transcription

Question 49

Where do MiRNAs bind to?

Answer 49

3' end of genes

Question 50

How can some genes be regulated by processes that affect translation or by modification of proteins?

Answer 50

Proteins bind 5' UTR. Affect availability of translation machinery.

Question 51

What is the levels of regulation for bacterial gene control?

Answer 51

Primary transcription

Question 52

What is the levels of regulation for euk gene control?

Answer 52

Many levels

Question 53

Is there cascades of gene regulation in bacterial gene control?

Answer 53

Yes

Question 54

Is there cascades of gene regulation in euk gene control?

Answer 54

Yes

Question 55

Is DNA-binding proteins important for bac gene control?

Answer 55

Important

Question 56

Is DNA-binding proteins important for euk gene control?

Answer 56

Important

Question 57

Is the role of chromatin structure important for bac gene control?

Answer 57

No, Absent.

Question 58

Is the role of chromatin structure important for euk gene control?

Answer 58

Important

Question 59

Is negative and positve control present in either bac or euk gene control?

Answer 59

Both present

Question 60

How is the initiation of transcription in bac and euk gene control?

Answer 60

Bac-Simple. Euk-Complex

Question 61

Are enhancer common in bac and euk gene control?

Answer 61

Bac-Less common. Euk-common

Question 62

How does transcription and translation occur in bacterial gene control?

Answer 62

Simultaneously.

Question 63

How does transcription and translation occur in euk gene control?

Answer 63

separately

Question 64

How common is regulation by small RNAs in bac and euk gene control?

Answer 64

bac- rare. Euk- common.