Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MB 414 > Regulation I > Flashcards

Regulation I Flashcards

1
Q

how many ATP are used for protein synthesis?

A

2 million ATP per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

levels of regulation

A
  • transcriptional
  • translational
  • level of activity of enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

best to regulate at

A

transcriptional level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

anabolic pathways

A

make if you need it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

catabolic pathways

A

break down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

operon

A
  • all use same promotor
  • group of genes grouped together that are all part of the same transcriptional unit.
  • multiple open reading frames
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

hydrogenase formula

A

H2 = 2 H+ to 2 e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

hydrogenase operon of B. japonicum

A
  • 4 operons
  • 4 promotters
  • each promotor slightly different.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

1st operon

A
  • hupUV regulate hydrogenase synthesis - on all the time
  • transfers signal to hoxXA and turns on genes
  • encoded by hupSL
  • hydrogenase typically turned off
  • only expressed when
    • hydrogen to eat
    • nickel to make active site
    • O2 to accept electron.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

2nd operon

A
  • hup SLCDF contains hydrogenase and needs to be on when condition are right
  • chaparones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3rd operon

A
  • proteins to put hydrogenase together

- structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

4th operon

A
  • always on

- sensors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

transcriptional control

A
  • keep the gene from being transcribed
  • do at the promoter
  • usually done by either helping (positive control) or preventing (negative control) the RNA polymerase from binding to the promotor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DNA binding proteins

A
  • can bind to DNA backbone or either major or minor groove.

- to interfere with RNA pol binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

helix-turn-helix

A
  • the helices fit into the major groove of B-DNA

- they usually bind as dimers to dual half sites on the DNA centered 10 bp apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

activators

A

bind to DNA and have region that contact RNA pol to make more active, get more RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

dioxic growth

A
  • 2 phase growth

- depletes all glucose first then goes to lactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Adaptation and Lactose

A
  • if lactose is absent, none of the gene products are present
  • if lactose is present as the sole sugar source, the gene products appear in near equimolar amounts
  • if lactose is removed as the sole sugar source, new gene products are no longer made and previously made enzymes decay.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

LacZ

A

encodes B-galactosidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

LacY

A
  • a permease

- lactose transporter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

LacA

A

a transacetylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

LacI

A
  • regulatory protein

- repressor

23
Q

Plac

A

operon for LacZ, LacY, and LacA

24
Q

Operator

A

regulatory proteins bind

25
Q

uninduced lac operon

A

repressor can bind

26
Q

induced lac operon

A

no repression

27
Q

no lactose

A

lacI always made and binds to operator to repress

28
Q

with lactose

A

LacI binds to allolactose and won’t bind to operator

29
Q

How does glucose repress lac?

A
  • lac operon regulated by levels of cAMP
30
Q

when glucose present,

A
  • level of cAMP low
31
Q

when glucose levels decline

A
  • adenylate cyclase is activated and catalyzes formation of cAMP from ATP
  • now higher levels of lactose
32
Q

Catabolite activating protein

A
  • CAP binds to cAMP and the complex activates lac operon to break down lactose
  • CAP is a DNA binding protein that activates many different (100) promoters
  • global regulator
33
Q

Arabinose operon

A
  • E. Coli can grow on arabinose when glucose is depleted, but in order to do so, needs to turn on an operon to use the substrate
  • turn on araA, arak, and araD
  • convert to xylulose-5-phosphate and shuttled to pentose phosphate pathway
34
Q

AraC

A
  • regulator

- can be activate ( in presence of arabinose) or repress (in absence of arabinose) the ara operon

35
Q

binding sites for AraC

A
  • operators
  • 4 of them
  • araO2, araO1, araI1, and araI2
36
Q

no arabinose

A
  • araC binds to 2 operators (one far away from promotor and one near) and loops out DNA
  • araC monomers dimerize and transcription inhibited
  • binds to O2 and I1
37
Q

with arabinose

A
  • arabinose fills in binding sites
  • AraC changes conformation and loses affinity for O2
  • binds to two adjacent operator sequences near promotor and allows for transcription.
  • binds to I2 and I1 now
38
Q

trp operon

A
  • encodes the enzymes for tryptophan biosynthesis

- only make when you don’t have product

39
Q

1st level of regulation of trp

A
  • transcriptional
  • the trp repressor, when bound to tryptophan, will bind to the trp operator, repressing transcription.
  • If trpR loses bound tryptophan, it falls off operator and transcription resumes.
40
Q

2nd level of transcription

A
  • at high trp levels, transcription of the structural genes will be terminated at attenuator sequence
41
Q

excess tryptophan

A
  • as mRNA is transcribed, the attenuator stem loop forms
  • ribosome not stalled because tryptophan still there.
  • sequence 1 and 2 form a loop and allow sequences 3 and 4 to form a transcriptional terminator.
  • regions 3 and 4 will form a G-C rich stem loop with a oligo-U sequence.
  • stops transcription before the rest of the operon is transcribed.
42
Q

tryptophan starved condition

A
  • sequence 3 is unavailable to make the transcriptional terminator, so transcription continues
  • there is no tryptophan so the ribosome stalls at the tryptophan codons
  • sequence 1 can’t bind to sequence 2
  • sequence 2 now binds to sequence 3 and transcriptional terminator does not form.
43
Q

anti sigma factors

A
  • if an alternate sigma factor of RNA polymerase is needed for transcription, some negative regulators act to bind the sigma factor and keep it rom recruiting RNAP
  • obscuring DNA recognition domain.
44
Q

FlgM

A
  • anti sigma 28
  • represses transcription of flagellin (structural subunit) until motor and hook have been made.
  • only want flagellin when assembling flagella
  • flagella assembled outside of cell, so flagellin needs to be transported through hole made up of motor and hook.
45
Q

Class I

A

master regulator

46
Q

Class II

A

assembly of the basal body - hook protein, and FlgM

47
Q

Class III

A

assembly of the filament, sigma 28 regulated

48
Q

When FlagM drops

A

sigma 28 recognizes promoter and RNA polymerase transcribes flagellin.

49
Q

Two component regulatory system

A
  • not convenient to bring compound being sensed into close contact with promotor
  • composed of a sensor and a response regulator
  • the sensor is a kinase (transfers a phosphate form ATP)
  • most sensors are an autokinase
  • sensor transfers phosphate onto regulator (aspartic acid residue), which becomes activated and allows transcription to occur
50
Q

auto-kinase

A
  • meaning they transfer the phosphate to themselves upon sensing the environmental signal on a histidine residue.
51
Q

Quorum sensing

A
  • cell to cell signaling in bacterial communities
  • autoinducers made at low levels and exported into medium.
  • cells measure levels of AI to determine how many other cells are present
  • few cells - low amount of AI
  • many cells - high amounts of AI
52
Q

Vibrio fischeri quorum sensing

A
  • produce light when large concentration of cells
  • AI is a homoserine lactone
  • autoinducer synthase and the LuxR are always
  • If enough AI sense LuxR will bind to AI allowing to dimerize and turn on luciferase
53
Q

Actyl-HSL mechanism

A
  • make acyl-HSL

- At high enough levels will bind to LuxR and turn on transcription of luciferase

54
Q

biofilm formation

A
  • regulate toxin production when a lot of bacteria around
  • don’t waste resources
  • controlled by LuxR type regulators
  • if attach to surface, produce alginate when a lot of other bacteria are around to form biofilm.

MB 414 (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions