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MBB 231 > Midterm 3 > Flashcards

Midterm 3 Flashcards

1
Q

what are the components of the endomembrane system

A
  • rough ER
  • Smooth ER
    -Endosomes
    -lysosomes
    -transition /transport/secretory vesicles
  • perioxisomes
  • vacuoles
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1
Q

what are the RER and SER the sites for

A

lipid and protein synthesis

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2
Q

what do lysosomes do

A

digest ingested material and unneeded cellular components

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3
Q

what does a peroxisome do

A

house hydrogen peroxide generating reactions

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4
Q

what do vacuoles do

A

store ions, sugars, amino acids, and toxic compounds

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5
Q

what do endosomes do

A

transport

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6
Q

what is the lumen

A

the internal space in the ER

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7
Q

where are polypeptides synthesized

A
  • 1/3 in the RER
  • 2/3 on free ribosomes
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8
Q

what polypeptides are synthesized in RER

A

secreted proteins

transmembrane proteins

soluble proteins that reside in ER, Golgi, lysosomes, edosomes, vesicles, vacuoles

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9
Q

what polypeptides are synthesized in free ribosomes

A

proteins destined to remain in cytosol

peripheral proteins of the cytosolic surface on membranes

proteins that are transported to the nucleus

proteins that are incorporated into peroxisomes, chloroplasts, and mitochondria

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10
Q

where do all proteins begin synthesis

A

on ribosomes in the cytosol

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11
Q

how does ER know where proteins go

A

info is coded in ER signal sequence

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12
Q

where does translation start

and what happens

A

the cytosol

mRNA leaves nucleus and associates with free ribosomes

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13
Q

when do polypeptides diverge to what pathway for routing and what are they

A

after translation

free ribosomes

ER docked ribsomoes

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14
Q

what are the 2 pathways protein sorting involves

explain them

A
  • co-translational import : proteins carrying an ER sequence direct the ribosome polypeptide complex to RER, translation is completed on RER
  • post translational import: proteins lacking an ER signal sequence complete their synthesis on free ribosomes , and are then released into cytoplasm with organelle-specific sorting signal
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15
Q

what sorting proteins do cytoplasmic proteins have

A

none

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16
Q

what is a polysome

A

multiple ribosomes synthesizing from the same mRNA

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17
Q

what does the signal hypothesis propose

A

that intrinsic molecular signals determine the location of some polypeptides

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18
Q

what happens if a sorting signal is deleted

A

targeting of protein is lost

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19
Q

what does the ER signal sequence usually have

A

hydrophobic N-terminal region and a polar region near the cleavage from the mature protein will take place

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20
Q

what does the signal recognition particle (SRP) bind

A

binds to ribosome mRNA polypeptide complex to the ER membrane

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21
Q

what does the SRP contain

A

proteins and RNA

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22
Q

what happens when the SRP binds to the signal sequence

A

blocks further translation

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23
Q

what happens once the SRP has been released

A

the ER signal sequence is inserted into the translocon (a channel protein)

this contact displaces the plug, opening the channel to the ER lumen

As protein elongates it passes into the lumen

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24
Q

what happens when polypeptide synthesis is complete (RER)

A

the polypeptide is released into the lumen and the ribosome detaches from the ER membrane

subunits dissociate and release mRNA

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25
Q

what do GTPases (G proteins) do

A

act as molecular switches

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26
Q

what is an example of a G protein

A

SRP

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27
Q

what are the two types of membrane proteins

A

single and multi-pass

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28
Q

what does asymmetry reflect

A

function

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29
Q

where are oligosaccharides always present

A

on the non-cytosolic side

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30
Q

where can hydrophobic transmembrane domains dissolve into lipid bilayer

A

through a seam along one side of the translocon

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31
Q

what determines the orientation of a multipass/integral protein

A

determined by the charge/orientation of the first transmembrane domain

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32
Q

what must each subsequent transmembrane domain have

A

opposite charge as one before

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33
Q

what is the ER the site of

A

protein synthesis

protein modification/maturation

recognition and removal of misfolded proteins

lipid synthesis

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34
Q

how does ER modify/mature proteins

A

glycosylation ( = glycoproteins)

folding of polypeptide chains and subunit assembly

disulphide bond formation

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35
Q

how does ER recognize and remove misfolded proteins

A

ER associated degradation (ERAD) recognizes misfolded proteins

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36
Q

where do misfolded proteins get degraded

A

cytosolic proteases

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37
Q

what happens to most proteins are the ER

A

they are glycosylated
(N-linked glycosoylation)

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38
Q

what does Golgi do in glycoslyation

A

modifies it

adds O linked sugars

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39
Q

what do carbohydrate groups function as

A

macromolecule bonding sites

aid in protein folding

increase stability

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40
Q

when is the oligosaccharide added to the recipient protein

and what is it called

A

as the polypeptide is being synthesized

called co-translational glycosylation

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41
Q

where do polypeptides fold into their final shape (ER)

A

in ER lumen

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42
Q

what are lectins and give 2 examples

A

carbohydrate binding proteins

Calnexin and calreticulin

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43
Q

what do calnexin and calreticulin do

A

bind to N linked oligosaccharides, preventing aggregation and promoting proper folding

drives disulphide bond formation

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44
Q

when does calnexin and calreticulin binding happen

A

after processing the oligoscacchardide precursor has begun

since they recognize a single terminal glucose

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45
Q

what is binding protein (BIP)

A

a chaperone in ER lumen

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46
Q

what does BIP do

A

binds to hydrophobic regions of polypeptide chains and prevents aggregation of polypeptides with similar regions

prevents interaction between hydrophobic regions of different proteins

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47
Q

what does the enzyme protein disulphide isomerase (PDI) do

A

catalyzes disulphide bond formation in ER lumen

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48
Q

in eukaryotic cells where is the only place disulphide bonds are formed

A

ER lumen

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49
Q

where do disulphide bonds form when protein is being synthesized

A

between adjacent cysteines

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50
Q

what activates the unfolded protein response (UPR)

A

when proteins are made faster than they are folded, processed, and transported

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51
Q

what happens when UPR is activated

A
  • phosphorylate translation factors (inhibits protein synthesis to decrease the flow of proteins into ER)
  • upregulate the expression of: ER based chaperones, transport that move proteins out of ER, and protein degradation machinery
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52
Q

where are degraded proteins identified by ERAD degraded

A

in proteasome in cytosol

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53
Q

what are proteasomes

A

large protein degrading structures

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54
Q

what do proteasomes bind to and what do they do after

A

ubiquitin-labelled proteins

they hydrolyze peptide bonds in an ATP-dependant manner

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55
Q

what joins ubiquitin to target protein

A

by a process involving 3 enzymes:

  • ubiquitin activity enzyme (E1)
  • ubiquitin conjugating enzyme (E2)
  • ubiquitin ligase or substrate recognition protein (E3)
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56
Q

what is the primary source of membrane lipids including phospholipids and cholesterol

A

ER

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57
Q

where are fatty acids for membrane phospholipids synthesized

A

cytoplasm

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58
Q

how do fatty acids get from cytoplasm to lumen side of bilayer

A

transferred by phospholipid translocators (flippases)

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59
Q

what does the the type of phospholipid transferred across the membrane depend on and what does it lead to

A

the particular translocator present

leads to membrane asymmetry

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60
Q

what of lipid lipid transfer proteins do and what does this allow

A

exchanges lipids between compartments

allows for the movement of phospholipids to membranes outside the endomembrane system

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61
Q
A
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62
Q

what does the golgi complex do

A

further processes and sorts glycoproteins and membrane lipids playing a central role in membrane and protein trafficking in eukaryotic cells

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63
Q

where are proteins released into ER lumen routed to

A

golgi, secretory vesicles, lysosomes, or back to ER

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64
Q

what is the TGN and what does it do

A

Vesicle sorting station

segregating proteins into vesicles headed to plasma membrane or other intracellular destinations

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65
Q

what is the CGN and what does it do

A

transition vesicle sorting system

sorting of proteins to be sent back to the ER or onto the golgi

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66
Q

what is glycosylation

A

addition of carbohydrates side chains to proteins

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67
Q

what is terminal glycosylation and where does it occur

A

modifications of glycoproteins through the removal/addition of sugar side chains on the core oligosaccharide (which is added in ER)

This occurs in golgi

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68
Q

what side of membrane does glycosylation occur

A

luminal (interior)

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69
Q

what is each step of glycosylation strictly dependent on

A

the preceding modification

addition of next sugar relies on the presence of the previous carbohydrate

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70
Q

what are the functions of glycosylation

A

-participate in protein/lipid sorting in the trans-golgi network

  • makes glycoproteins/membranes more resistant to digestion by proteases by creating the glycocalyx
  • serve as recognition molecules in cell-cell interaction
  • regulatory roles (Poetin folding/stability), blood type, immune regulation

essentially gives cell ability to generate many chemically distinct molecules on cell surface

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71
Q

what are the two hypotheses for movement through golgi

A

stationary cisternae model: cisternae and the resident enzymes stay in place, while cargo moves from one stack to the next

cisternae maturation model: cargo remain within a cisternae, while the cisternae move forward ( cis to trans) and resident enzymes shuttle backwards in vesicles

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72
Q

what is anterograde transport and example

A

movement of material toward plasma membrane

ex: exocytosis

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73
Q

what is exocytosis

A

fusion of vesicle with the plasma membrane, releasing their contents into the extracellular

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74
Q

what is retrograde transport and an example

A

movement of materials towards ER and away from plasma membrane

ex: endocytosis

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75
Q

what is endocytosis

A

formation of vesicle on the plasma membranes, taking up solutes from the extracellular space

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76
Q

what are the ways that a protein is kept within an organelle

A
  • retention: resident molecules are excluded from transport vesicles
  • retrieval: tags can be used to return escaped proteins to their proper locations
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77
Q

what is a tag made of

A

depending on the protein/destination can be an amino acid sequence, a hydrophobic domain, or oligosaccharide side chain, or something else

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78
Q

what is the most common ER retrieval tag

A

KDEL retrieval signal

returns soluble protein back to ER

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79
Q

what is the sequence in KDEL

A

Lys-Asp-Glu-Leu

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80
Q

what is the most common amino acid sequence for ER specific retrieval/retention signals

A

Lys-Lys-any-any

81
Q

what happens if KDEL proteins leave ER (they are ER residents)

A

they associate with KDEL receptor

binding is efficient in the lower pH environment of the golgi

82
Q

what do KDEL receptors mediate

A

packaging of KDEL proteins into ER bound transport vesicles

83
Q

when KDEL receptors release KDEL proteins in ER is the binding efficient

A

no, since ER has high pH

84
Q

what are the functions of the proteins vesicles are coated in

A
  • curve the membrane to form the vesicle
  • select the components to be carried by the vesicle
85
Q

what are the 2 protein layers vesicles are composed of and what do they do

A

outer layer: acts as scaffolding to cage around the vesicle

inner layer: acts as an adapter between the outer layer and the lipid bilayer/cage. Selects cargo proteins through affinity interactions with cytoplasm domains or these transmembrane proteins

86
Q

what are the classes of coated vesicles

A

COP11 coated vesicles

COP1 coated vesicles

clathrin coated vesicles

87
Q

what do COP11-coated vesicles do

A

move materials from the ER forward (integrate transport) to the ERGIC (ER-golgi intermediate compartment, AKA vesicular tubular cluster) and golgi

88
Q

what do COP1- coated vesicles do

A

move materials from the ERGIC and golgi backward (retrograde transport) or from the trans golgi to the cis golgi cisternae

89
Q

what do the clathrin-coated vesicles do

A

move materials from the plasma membrane backwards and the TGN to the endoscopes/lysosomes/plant vacuoles

90
Q

does COP11 or COP1 associated with budding

A

COP11

91
Q

what initiates budding

A

by recruitment of the small GTP binding protein (GTPases) SAR-GDP to a patch of donor membrane

92
Q

how do vesicles move to their destination

A

mediated by microtubules

like a train (motor protein) pulling cargo (vesicle) along train tracks (microtubules)

93
Q

what does the initial contact between a vesicle and a target membrane involve

A

tethering proteins

94
Q

what are the 2 types of tethering proteins

A

rod shaped fibrous proteins that form long bridges

multi protein complexes that hold 2 membranes close together

95
Q

what is most of the specificity in tethering proteins conferred by

A

Rab GTPases

96
Q

how does Ran GTPase work

A

it receipts the cytosolic tether proteins to the membrane surface, allowing docking to occur

also plays a role in recruiting motor proteins to vesicles to facilitate transport

97
Q

what do SNARE proteins do

A

mediate fusion between vesicles and target membranes

98
Q

what does the SNARE hypothesis explain

A

states that the sorting and targeting of vesicles involves 2 families of SNARE (snap receptor) proteins

99
Q

what are the 2 families of SNARE proteins

A

V SNARE: vesicles SNAP receptor. found on vesicles

T SNARE: target SNAP receptors, found on target membranes

100
Q

How to V and T SNARES pull membranes together

A

alpha helices intertwine

101
Q

what does dissociation of V and T SNARES require

A

NSF (N-ethylmalemide-sensitive factor) and SNAPs (soluble NSF attachment proteins) to pry apart the SNARES using energy from ATP hydrolysis

102
Q

what happens after V and T SNARES are separated

A

V SNAREs are shuttled back to the previous compartment to repeat the process

103
Q

what is constitutive secretion

A

after budding form TGN, vesicles move directly to the cell surface and immediately fuse with the plasma membrane

104
Q

what is regulated secretion

A

secretory vesicles that accumulate in the cell and only fuse with plasma membrane in response to specific signals (ex: Ca 2+)

105
Q

what is polarized secretion

A

specific proteins are secreted form a limited region of the plasma membrane

106
Q

give 2 examples of cels that use polarized secretion

A

neurotransmitters are only secreted at nerve junctions

intestinal cells secrete digestive enzymes out of the intestinal side of the cell

107
Q

how does polarized secretion work

A

proteins/lipids destined for polarized secretion are sorted into vesicles that have receptors that bind to localized sites on plasma membrane

108
Q

what is a primary way cells maintain their membrane fluid balance

A

bulk phase endocytosis (clathrin - independent endocytosis)

109
Q

is bulk phase endocytosis specific

A

no

110
Q

what rate does bulk phase endocytosis go at

A

constant

111
Q

what does bulk phase endocytosis compensate for

A

plasma membrane gains by exocytosis and maintaining surface to volume ratio

112
Q

how can checks selectively and efficiently acquire macromolecules

A

by receptor mediated endocytosis (clathrin dependent endocytosis(

113
Q

what are the steps of receptor mediated endocytosis

A
  1. specificity molecules (ligands) bid to their receptor on the outer cell surface
  2. as the receptor-ligand complex diffuse laterally they encounter specialized regions called coated pits (sites for collection and internalization of these
  3. accumulation of complexe sin the pits trigger the accumulation of clathrin-coat proteins on the cytosolic side of the membrane inducing a curvature of the pit
  4. pit will eventually pinch off, forming a coated vesicle s
114
Q

do clathrin coated vesicles differ from COP11 vesicles in their formation and proteins

A

yes

115
Q

what is required as clathrin accumulates around the budding vesicle and what does it do

A

dynamin

constricts and closes the vesicle

116
Q

is dynamin a GTPase

A

yes

117
Q

what is phagocytosis

A

ingestion of macromolecules, cell parts, or whole organisms

118
Q

in humans what cell does most of phagocytosis

A

white blood cell

119
Q

how does phagocytosis work

A

contact with the target triggers the onset of phagocytosis, as folds in the membrane (pseudopods) surround the object forming an intracellular phagocytic vacuole (or phagosome)

120
Q

what happens to mist material taken up by cell

A

destroyed by lysosomes

121
Q

what acid do lysosomes contain

A

acid hydrolyses capable of degrading major classes of macromolecules

122
Q

what is acid hydrolase

A

a hydrolytic enzyme with optimal pH of 5

123
Q

are lysosome lumen’s basic or acidic

and why

A

very acidic

essential for the functioning of acid hydrolases

124
Q

what is a endocytic vesicle

A

the vesicle budding from the plasma membrane as a result of bulk phase or receptor-mediated endocytosis

125
Q

what is an early endosome

A

the primary sorting station in the endocytic pathway

126
Q

what is a late endosome

A

an organelle containing the full complement of acid hydrolase but who’s lumen has not reached the pH of 4-5

127
Q

what is a lysosome

A

an organelle that is digestively active (all hydrolases and correct pH)

128
Q

What are the 2 routes for a late endosome to mature into a lysosome

A
  1. the ATPase pumps can lower the pH of the late endosome, which activates the enzymes
  2. the late endosome can fuse with an existing lysosome
129
Q

what are the 2 types of receptors in endocytic pathway

A

housekeeping receptors

signalling receptors

130
Q

what does a housekeeping receptor do

A

mediate the uptake of material that will be used by the cell

131
Q

how does signalling receptor work

A

bind extracellular messengers that change the activity of the cell

132
Q

what happens after signalling receptors bind

A

receptors get degraded (receptor down regulation), reducing the sensitivity of the cell to the further simulation

133
Q

what is a residual body

A

indigestible materials that remain in the lysosome

134
Q

what do cells do with cellular waste

A

some release contents

some accumulate them and it contributes to cellular aging

135
Q

what is autophagy

A

the digestion of old organelles

136
Q

what is macrophagy

A

formation of an autophagic vacuole (autophagosome) when an organelle becomes wrapped in a double membrane derived from the ER

137
Q

what is macrophagy

A

a small vacuole is formed surrounded by a single membrane

138
Q

what allows polypeptides to enter organelles after they’ve been synthesized

A

post-translational import

139
Q

what do proteins getting imported to the ER need

A
  • sorting signal
  • receptor
  • membrane transporter
140
Q

what is a peroxisome

(structure and defining characteristic)

A

spherical organelle, bounded by single membrane

defining characteristic is the presence of catalase

141
Q

what are the functions of peroxisomes

A
  • H2O2 metabolism (balance)
  • detoxification of harmful compounds
  • oxidation of fatty acids
  • metabolism of N-containing compounds
  • catabolism of unusual substances
142
Q

how are peroxisomes formed

A

generated by division of peroxisomes or by vesicle fusion

143
Q

how do peroxisomal proteins get into peroxisomes

A

either synthesized by peroxisomal enzymes

or transported there by lipid transfer proteins

144
Q

where are most peroxisomal enzymes synthesized and transported

A

free ribosomes

post translationally imported via a C terminal peroxisomal targeting signals (PTS 1)

145
Q

where are most mitochondrial and chloroplast polypeptides synthesized

A

free ribosomes

146
Q

what allow passage of small molecules in outer membrane in mitochondria/chloroplasts

A

porins

147
Q

how does translocation across both membranes work in mitochondria

A

occurs simultaneously at sites where the inner and outer membranes are close together

uses transport complexes called TOM and TIM

148
Q

what does TOM and TIM stand for

A

Translocase of the Outer Mitochondrial membrane

Tranlocase of the Inner Mitochondrial membrane

149
Q

how is targeting of mitochondrial proteins done

A

1 - cytosolic proteins are bound by molecular chaperones to keep them in an unfolded state

2- presequences encoded by am N-terminal alpha helix (containing positively charged and hydrophobic amino acid residues) binds the receptor component of TOM, and is positioned into the TOM

3- during transport of proteins destined for the matrix, the TOM and TIM channels are brought together

4- movement into matrix is powered by electrical potential ( matrix is more negative, pre sequence is more positive)

5- then mitochondrial proteins are pulled into matrix ( either by chaperones or Radom diffusion)

6- once in the matrix, the presequence is cleaved by a peptidase and the protein is folded into its native conformation

150
Q

what do all chloroplast proteins have

A

a stroma targeting domain which is removed by a peptidase upon transport

151
Q

what is a thylakoid transfer protein needed for

A

for entry into the thylakoid

(for nuclear genes)

152
Q

are some thylakoid membrane proteins co-translationally inserted

A

yes, chloroplast genes

153
Q

through what does traffic continuously travel through between nucleus and cytosol

A

nuclear pores

153
Q

what are nuclear pores

A

specialized channels in the nuclear envelope where inner and outer membranes are fused

provides direct contact between cytosol and nucleoplasm

154
Q

what speed to small particles pass through nuclear pores

A

speed proportional to their size

155
Q

how are proteins that are too big to freely diffuse getting in nucleus

A

through active transport

nuclear localization signals (NLS) and nuclear export signals (NES) enable proteins to be recognized and transported by the nuclear pore complex

156
Q

what is the general structure of NES and NLS

A

contain proline and positively charged amino acids

157
Q

what provides energy to transport proteins through nuclear pores

A

hydrolysis of GTP by GTPase

158
Q

what does protein isolation start with

A

mechanical disruption (homogenization)

chemical disruption (lysis)

159
Q

what is homogenization

A

rupturing cell to release the cell contents

160
Q

what do we want cell homogenates to have

A
  • disrupted plamsa membrane
  • released soluble proteins
  • maintain the integrity of organelles (or create microsomes)
161
Q

why do you often add protease inhibitor in lysis

A

to prevent protein degradation

162
Q

what is an isotonic buffer used for in lysis

A

break apart cell but not the organelles

163
Q

what gives you a cell slurry

A

combination of mechanical and chemical disruptions

164
Q

can harsh lysis buffers (amphipathic detergents) be used

A

yes, though these denature the protein

165
Q

what separates different organelles/micromolecules in centrifuges

A

different sedimentation rates

166
Q

what is differential centrifugation

A

separation of particles/organelles of different sizes and density by their rate of sedimentation

167
Q

in differential centrifugation what size particles end up on bottom

A

larger ones
(bigger sedimentation coefficient)

168
Q

what is sedimentation coefficiemt relative to

A

size/density of a molecule

169
Q

what does sedimentation coefficient measure

A

how rapidly the particle sediments when subjected to centrifugation

170
Q

how does density gradient centrifugation work

A

samples are placed on top of gradient (often sucrose) and centrifugation causes particles to move into discrete zones based on their density and the density gradient

dense particles move into gradient faster

171
Q

what is chromatography

A

a procedure where a mixture of dissolved components is fractionated as it moved through some type of porous matrix (usually a column)

172
Q

what does ion-exchange chromatography rely on

A

differences on surface charge of macromolecule

173
Q

how does ion exchange chromatography work

A

beads carry a weak charge, and charged proteins react to beads to varying degrees, separating them

174
Q

what happens as pH is lowered in ion exchange chromatography

A

negatively charged amino acids become neutral

positively charged amino acids become more abundant

175
Q

what does gel filtration chromatography rely on

A

differences in size and shape of macromolecule

176
Q

how does gel filtration chromatography work

A

beads have different sized pores that allow proteins to go through them gradually

larger proteins get through faster

177
Q

what does affinity chromatography rely on

A

specific interactions between a ligand/substrate/antibody and the target

178
Q

how does affinity chromatography work

A

beads have specific molecules attached to their surface and preferentially bind to the protein being purified

179
Q

what is immuniorecipitation

A

when antibodies are used in affinity chromatography

180
Q

what type of chromatography usually results in a near total purification of the desired molecules in a single step

A

affinity chromatography

181
Q

what is electrophoresis

A

a group of techniques that use an electric field

182
Q

what is electrophoresis useful for

A

for characterizing a mixture of soluble proteins

183
Q

what does how quickly a molecule moves during electrophoresis depend on

A

shape, charge, size

184
Q

what are detergents

A

amphipathic molecules that disrupt the lipid bilayer, disrupts hydrophone interactions, and thus dissolved the lipids

185
Q

what often happens prior to electrophoresis

A

insoluble and soluble proteins are exposed to high heat and SDS which disrupts protein-protein and protein-lipid associations

186
Q

what are examples of disulphide bond reducing agents

A

Beta - mercaptoethanol

dithiothreitol (DTT)

187
Q

how does an SDS PAGE work

A
  • denature sample with SDS
  • Apple mixture of proteins on gel, apply electric field
  • negatively charged proteins/SDS move towards positive Botton of gel
  • smaller ones move faster
  • proteins end up in decreasing size down the gel
188
Q

what is 2D SDS PAGE

A

separates proteins in 2 dimensions

first by charge, then by size

189
Q

how does mass spectrometry work

A
  1. proteins are digested by a protease to break them into smaller polypeptides
  2. polypeptides are separated by their mass/charge ratio
  3. computer analysis compares the spectrum with a database
190
Q

what is western blotting (immunoblotting)

A

after electrophoresis (SDS PAGE), polypeptides can be identified using it

proteins are transferred to a membrane and bound by specific antibodies

191
Q

what do hydridomas do

A

fuse a lymphocyte (antibody producing cell) to an immortalized myeloma cell (able to divide forever)

can produce a single antibody type and secrete it in the culture media for collection

192
Q

what are the steps of western blotting (immunoblotting)

A
  1. mixture is separated by SDS PAGE
  2. transferred to a membrane using an electric current
  3. incubated with a primary antibody, wash, then secondary antibody
  4. react with substrate and image
193
Q

what is a genome

A

entire set of info on DNA (includes coding and non coding)

194
Q

wha is a transcriptome

A

entire complement of RNA expressed by a genome

195
Q

what is a proteome

A

entire complement of proteins expressed by genome in a cell

196
Q

what is an interactome

A

map of the network of interactions between proteins in an organisms proteome

197
Q

what can hub proteins have

A

several binding sites or can bind different proteins at same time

single binding interface which is capable of binding several proteins at different times

198
Q

are hub proteins more or less likely to be essential for cellular survival

A

more likely

199
Q

what is chromatin immunoprecipitation (CHIP) for

A

finds where a protein binds within the genome of a cell

200
Q

what are 3 techniques to determine the 3D structure of a protein

A

X ray crystallography

nuclear magnetic resonance spectroscopy

cryo-electron microscopy

MBB 231 (5 decks)

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