Chapter 12 part 1

Question 1

_______ occurs or genes needed to continuously perform tasks and are needed for life of the cell

Answer 1

constitutive transcription

Question 2

_______ is needed in genes only needed for respones to changing environemental conditions or during certain phases of growth

Answer 2

regulated transcription

Question 3

_______ regulation is the major means of regulating gene expression in bacteria
- some _______ mechanisms are also important

Answer 3

transcriptional
post-transcriptional

Question 4

negative control of transcription involves binding of a(n) _______ protein to a regulatory DNA sequence and preventing transcription

Answer 4

repressor

Question 5

positive control of transcription involves binding of a(n) _______ protein to a regulatory DNA sequence and initiates transcription

Answer 5

activator

Question 6

Transcription factors all have at least 2 domains. What are they?

Answer 6

1) DNA binding domain
2) allosteric domain

Question 7

_______ domain locates and binds to operator DNA sequence or their target DNA sequences

Answer 7

DNA binding domain

Question 8

_______ domain binds a molecule or protein, which causes a change in conformation of the DNA-binding domain, altering its function

Answer 8

allosteric domain

Question 9

_______ regulation is where the effector molecule causes transcription to start

Answer 9

inducible

Question 10

_______ regulation is where the effector molecule causes transcription to stop

Answer 10

repressible

Question 11

In negative inducible control:
1) TF is a _______
2) binding of the effector molecule causes transcription to _______
3) effector molecule is a _______

Answer 11

1) repressor
2) start
3) inducer

Question 12

In negative repressible control:
1) TF is a _______
2) binding of the effector molecule causes transcription to _______
3) effector molecule is a _______

Answer 12

1) repressor
2) stop
3) co-repressor

Question 13

In positive inducible control:
1) TF is a _______
2) binding of the effector molecule causes transcription to _______
3) effector molecule is a _______

Answer 13

1) activator
2) Start
3) inducer

Question 14

In positive repressible control:
1) TF is a _______
2) binding of the effector molecule causes transcription to _______
3) effector molecule is a _______

Answer 14

1) activator
2) stop
3) inhibitor

Question 15

Bacterial regulatory DNA sequences frequently have _______ or _______ repeats; each polypeptide of a regulatory homodimer interacts with one repeat

Answer 15

inverted or direct

Question 16

What is the most common structure of a homodimer protein in bacteria?

Answer 16

helix-turn-helix (HTH) motif

Question 17

clusters of genes undergoing coordinated transcriptional regulation by a shared regulatory region are called _______

Answer 17

operons

Question 18

the _______ operon of E.coli is responsible for producing three proteins needed for use of lactose

Answer 18

Lactose (lac) operon

Question 19

_______ is the principal source of energy for E.coli and most organisms, while _______ is one of the sugar/carbon alternate sources

Answer 19

glucose
lactose

Question 20

Lactose is a disaccharide of _______ and _______

Answer 20

glucose and galactose

Question 21

Bacteria with a lac+ phenotype can grow on media containing _______ as the only sugar, while the lac- phenotype cannot

Answer 21

lactose

Question 22

bacteria produce a gated channel, _______, at the cell membrane that allows lactose to enter the cell and the enzyme _______ to break the β-galactoside linkage

Answer 22

permease
β-galactosidase

Question 23

the breakdown of lactose also produces a small amount of _______, which acts as an inducer compound

Answer 23

allolactose

Question 24

What are the three binding sites in the regulatory region of E.coli

Answer 24

1) CAP binding site
2) promotor (RNA pol)
3) operator (lac repressor protein)

Question 25

_______ gene, which encodes β-galactosidase

Answer 25

lacZ

Question 26

________ gene, which encodes permease

Answer 26

lacY

Question 27

_______ gene, which encodes transacetylase

Answer 27

lacA

Question 28

lacZ, lacY, and lacA are transcribed as a single _______mRNA, which is translated to produce the three distinct polypeptides

Answer 28

polycistronic

Question 29

The _______ gene encodes for the lac repressor protein

Answer 29

lacI

Question 30

The lacI gene is next to but not apart of the lac operon and is _______ expressed

Answer 30

constitutively

Question 31

The lac repressor protein is a _______. (shape)

Answer 31

homo-tetramer

Question 32

The Lac operon is an example of _______ control

Answer 32

negative inducible

Question 33

when allolactose binds to the allosteric domain of the lac repressor, the complex is called _______ complex

Answer 33

inducer-repressor