Brainscape's Knowledge GenomeTM

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


See full index

biochemistry Jonklaas > test 2: protein folding > Flashcards

test 2: protein folding Flashcards

1
Q

proteins become denatured by what

A

heating

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

protein denaturing causes the protein to what

A

unfold

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

what is a proteasome

A

causes misfolded proteins to get refolded or proteolyzed immediately
refolded meaning that it has no function

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

if the protein folds incorrectly what can happen to the cell

A

the cell can be killed

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

what happens to a protein after the polyubiquitin chain is attached to it

A

it signals to the cell that the protein needs to be destroyed so it undergoes protein degradation to cut it up and then it is refolded again into something that works

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

what chaotropic agents denature protein

A

guanidium chloride and urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what structure do chaotropic agents affect

A

interactions that stabilize 30 structure

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

what is christian anfinsen known for

A

the denaturation and renaturation of ribonuclease A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what was the denaturation and renaturation of ribonuclease A

A

RNase A is an enzyme that breaks down RNase
- treated RNase A with urea and mercaptoethanol ( both of these unfolded the protein)
- anfisen removed the urea and merca and the protein refolded
-Rnase A refoled into OG native structure and regained full enzymatic activity
- showed that the enzyme could refold back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what was the conclusion of the anfisen RNAse experiment

A
  • showed that the primary amino acid sequences contains all the information needed to specify the correct 3D structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

1o structure (sequence) codes for

A

3o structure

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

all the info needed to make a 3d structure is where

A

in 1o structure

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

what is favorable in protein folding

A
  • negative DG
  • negative DH
  • increase in S
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what specific energetic factors are favored

A
  • hydrophobic effect
  • formation of stabilizing interactions
  • entropy of water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the hydrophobic effect

A
  • non polar side chains are buried in the interior of the protein as it folds minimizing the exposure to water
  • increases the entropy of the water meaning that is a more negative G
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what interactions are formed during protein folding

A
  • hydrogen bonds: back bone and side chain
  • ionic interactions: oppositely charged amino acid
  • van de waals interactions: closely packed atoms in the folded state
  • disulfide bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is levinthals paradox

A
  • asking why proteins dont take forever to fold given that there can be so many shapes
  • proteins fold through limited and specific pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what happens during protein folding

A
  • polypep collapses due to the hydrophobic effect
  • 2o structure forms
    3o structure begins to form
  • final native state forms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what state is the most stable

A

the native state

20
Q

what shape does a protein fold in

A

a funnel

21
Q

what is in vitro

A
  • easy folding
  • folding by dilution in buffer
22
Q

what is in vivo

A
  • difficult to fold bc the cellular environment is crowded
  • co translational folding
  • high potential for misfolding and precipitation
23
Q

what are chaperone proteins

A

help proteins fold

24
Q

when were chaperone proteins discovered

A

during heat shock that is why theyare called heat shock proteins

25
Q

what energy does protein folding need

A

atp hydrolysis energy

26
Q

how is protein precipitation prevented

A

by DNAj and DNAk coating the unfolded protein and preventing denaturation/ precipitation

27
Q

what large chaperon protein helps fold proteins in prokaryotes, cytosol of eukaryotes

A

Hsp60

28
Q

where is the chaperone protein Hsp60 located

A

GroEL/GroES complex in E.coli

29
Q

what is important about the GroEL/GroEs folding mechanism

A

it requires ATP hydrolysis

30
Q

what is the purpose of disulfide isomerase

A

facilitates formation of correct disulfie bridges

31
Q

what does peptidyl proline isomerase do

A

catalyses cic-trans isomerisaton of peptide bonds involving proline

32
Q

what happens if a protein doesn’t get refolded

A

it can accumulate as precipitate which can resul tin severe chronic degenerative diseases that affect the brain and CNS

33
Q

what diseases are associated with precipitated proteins

A

Prion- transmissible spongiform encephalopathies TSE

34
Q

what are different types of TSE

A

BSE, mad cow diseaes, CJD/ nvCJD. human BSE

35
Q

what are amyloid related diseases that are from precipitated proteins

A

alzheimers, parkinsons

36
Q

what conformation changes when the protein misfolds

A

alpha helix turns into b sheet conformation and forms a cross B helicial core filament structure

37
Q

why is too much amyloid bad

A

it can form plaque in the brain and disrupt cell function and cause neuronal apoptosis which is brain cell death

38
Q

what can cause misfolding

A
  • caused by genetics
39
Q

what is a prion

A

proteinaceous infectious particle

39
Q

what happens in a prion

A
  • infection is when there is a change of 2o structure and conformation in the pathogenic protein and it converts from alpha to beta
40
Q

what is kuru and what disease do they have

A
  • tribe in papa new guniea and they ate dead loved ones and PrPSC prions were transmitted
41
Q

what is CWD

A

a neurological disease in deer, elk, ad moose

42
Q

why was it important that stanley prusiner won the nobel peace prizec

A

1st case of infectious agent being aprotein

43
Q

what is CTE

A

chronic traumatic encephalopathy a diseae that can lead to demntia memory loss and depression

44
Q

what protein can cause cancer if misfolded

A

p53 protein because it is a tumor supressor so it stops them before they grow if it is not working then it can cause them to grow

45
Q
A

biochemistry Jonklaas (13 decks)

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