Final Flashcards
(197 cards)
1
Q
What are the steps of creating lysosomes (5)?
A
Enzymes go through sec path (targeted bc n term hypho leader seq)
Thru ER via cotranslation (translocon)
In cis golgi, man 6 phosphate attached
M6P attaches to receptor in cis golgi, buds off in clathrin coated vesicle
fuses w/s endosome, change in pH releases M6P
2
Q
What direction do COP1’s travel?
A
Retrograde
3
Q
What direction do COP2’s travel?
A
Anterograde
4
Q
Through what does COP1 move materials?
A
Trans -> medial -> cis golgi
5
Q
What path do COP2 vesicles travel through?
A
RER -> cis golgi
6
Q
Where are clathrin coated vesicles found?
A
TGN
7
Q
When are clathrin coats used?
A
Recep mediated endocytosis
8
Q
What 2 shapes compose clathrin?
A
Pent, hexagons
9
Q
What two proteins are used to make clathrin?
A
Heavy/light chain
10
Q
What does the clathrin light chain do?
A
Holds heavy chains in place
11
Q
What does the clathrin heavy chain have?
A
Feet at end terminus
12
Q
What is the role of the clathrin triskels in vesicles?
A
Imparts curvature of membrane
13
Q
What’s another name for adaptor proteins and how many types are there?
A
Assembly particle, 4
14
Q
What is required to initiate vesicle formation?
A
ARF
15
Q
What does ARF stand for
A
ADP Ribosylation Factor
16
Q
How many ARFs are there?
A
6
17
Q
What are the 2 roles of ARFs?
A
GTP binding protein and GTPase
18
Q
What happens to ARF on binding GTP?
A
Shape change
19
Q
What tickles ARFs to switch GDP w/ GTP
A
GEF
20
Q
What proteins do SAR1 resemble?
A
ARF
21
Q
What do adaptor proteins recognize?
A
ARF on membrane, cargo
22
Q
Define heterotetramer
A
4 distinct protein complex
23
Q
What kind of polymer is AP2?
A
Heterotetramer
24
Q
What does GGA stand for (adaptor)
A
Golgi localized Gamma ear ARF (adaptor)
25
What is the address on a lysosomal hydrolase?
Mannose 6 Phosphate
26
What is released when ARF GPD is tickled and given GTP?
Lipid tail to insert into membrane
27
How does GGA know that M6P recep is the right recep
Address (YXX/O/)
28
What is AP2 used in?
Recep Med Endo
29
What subunit of AP2 does the C face of a membrane recep bind to?
Mu
30
What is inositol?
A glycolipid
31
What gives specificity to membranes
Different phosphorylations of inositol
32
What starts recep mediated endo?
Inositol 4,5 bisphosphate
33
How does RMEndo start?
AP2 changes shape after recognizing I(4,5)P2, binding a membrane receptor to mu subunit
34
Where are AP1,3,4 found?
Endosome or TGN
35
What does Dynamin use as energy to pinch off vesicles?
GTP
36
What protein starts COP2 ves form?
SAR1-GTP
37
In COP2 what inserts into the membrane to give curvature?
SAR1-GTP
38
What binds to SAR1-GTP in COP2
Sec 23/24
39
What binds to Sec 23/24 in COP2?
Sec 13/31
40
What do the receps in COP1 vesicles recognize?
KDEL amino sequence
41
What does RAB stand for
RAS-like protein isolated from rabbits (RAS are the family of ARF/SAR)
42
Where are RABs found?
On vesicles
43
What are attached to vesicular RABs?
VSNARE proteins (SNAP Receptors) (Snares)
44
What does the a helix in the VSNARE have (define heptag repeat)
(A)BC(D)EFG where A, D are hypho
45
What occurs when a vesicle bumps into target?
Tethering
46
Where are RABs found in membrane fusion
Vesicle and Target (both w/ GTP)
47
Where are RABs found w/o GTP?
Cytosol
48
What gives membrane fusion specificity?
Like RABs on Ves and Target
49
How does SNAP 25 insert itself in target membrane
Lipid tail
50
What's the neuroterm for VSNARE
synaptobrevin
51
What's the neuroterm for TSNARE
syntaxin
52
How are vesicles pinched off in membrane fusion?
VSNARE + TSNARE&SNAP25 zip together
53
What is and what does NSF do?
N-ethylmaleiamide sensitive factor, unzips SNARES/SNAPS
54
What does SNAP stand for?
Soluble NSF attach protein
55
What does NSF do?
ATP to unwind SNARES/SNAPS
56
Where is plasmalogen created, found?
Peroxisomes, myelin sheaths
57
What is plasmalogen and what is weird about it?
Phospholipid, attached to gycerol using ether
58
How is membrane potential usually distributed?
+ on outside
59
What does Botulism do?
Cleaves V/TSNARES
60
What depolarizes a membrane
Na+ entering cells
61
What depolarizes a membrane
K+ out
62
What happens when an action potential reaches synaptic cleft?
Ca+ enters cell, reacts w/ synaptogabin, cause vesicles to bind to membrane, empty into cleft
63
What do peroxisomes do?
Break down >22 carbon fatty acids, no ATP generation
64
What enzymes do peroxidases use to make hydrogen peroxide?
Oxidases
65
What molecule do peroxisomes detoxify?
Ethanol
66
What do peroxisomes use to convert H2O2 to water?
Catalase
67
What is the address on peroxisomal enzymes and where is it found?
SKL, C terminus
| PTS1 (peroxisomal targeting sequence 1)
68
What is the name for peroxisomal enzymes?
Peroxins
69
In what shape are peroxins carried in?
linearly
70
How many bilayers does the nucleus have?
2
71
What occurs in the nucleolus
rRNA produced, Ribosomes assembled
72
Outermembrane of nucleus contiguous with
RER, SER
73
What is the space between the nuclear bilayers
Perinuclear space
74
What attachement sites are found on the inside of the inner nuclear membrane
Lamina, mesh, attaches to chromatin
75
What are the attachment sites on the outside of the outer nuclear membrane and what do they bind to?
Nesprin 1/2 bind actin
| Nesprin 3 binds int fils
76
What are nuclear lamins composed of and what are those pieces called?
Intermediate filaments, called lamina
77
What are the three compnent pieces of nuclear lamins and how are they hooked up?
A, B, C
| A bound to C, both bound to B which is bound to the membrane
78
What destroys lamins before mitosis?
Phosphorylation by MPF which is a cyclin dependent kinase
79
What does a defect in nuclear lamins cause
Progeria
80
What proteins are allowed to enter the nucleus?
Have NLS (Nuclear localization signal)
81
What is the NLS (Nuclear localization signal?
PKKKRKV
82
What is on the C face of the nuclear pore?
Annulus, octoganal repeating protein complex
83
What is a nuclear pore protein called?
Nucleoporin
84
How many proteins compose the (8)n repeating annulus complex?
30
85
What radiates from the C face of nuclear pores?
Cytoplasmic filaments
86
What does the N face of the nuclear pore look like?
Basket
87
What is the main feature of the nucleoporins in the nuclear pore?
Fg repeats (phenylalanine glycine)
88
Where is importin alpha originally and what does it look for to bind to?
In cytosol, looking for PKKKRKV (NLS) on proteins
89
What finds and binds importin alpha?
Importin beta
90
What happens to importin beta once it binds alpha bound to protein cargo
Cytoplasmic filaments grab it and carry it through the membrane
91
What is an important feature of importin beta?
Fg repeats
92
What occurs once the importin complex enters the nucleus
RAN-GTP binds Imp beta, releasing Imp alpha and protein
93
Once RAN-GTP binds Imp beta what happens
Moves back into the cytoplasm
94
What happens once RAN-GTP+Imp B enters cytosol
RAN-GAP converts GTP=>GDP, releasing Imp B
| RAN-GDP reenters nucleus where it is tickled by RAN-GEF
95
What family of proteins does RAN belong to and what are 3 examples?
RAS
| SAR1, ARF, RAB
96
How is Imp A removed from nucleus
Exportin finds Nuclear Export Signal on it, binds and carries out
97
What are histones, what is their charge and what are the variaties
H1, H2A, H2B, H3, H4
98
Describe hyperacetylation
Histone acetylase attaches acetyl groups to histones, tightening and repressing transcription
99
How is DNA coiled?
Negatively supercoiled
100
Where are coding genes located
tips of cohesin loops
101
@ n terminus of histones, what affects gene expression
Acetylation on lysine
| Methylation of argenine/lysine
102
What kind of chromatin is always ready for transcription
Euchromatin
103
What is the telomerase gene sequence
TTAGGG
104
What is the Hayflick limit
Max times a cell can divide
105
What is a feature of mitochondrial outer membrane porins?
B pleated sheets
106
What are 4 features of the mitochondrial inner membrane
Cardiolipin, ATP synthase, cristae, ETS
107
Where is cardiolipin found and what does it do?
Mitochondrial inner membrane
| Impermeabilizes membrane to p+, holds protein pumps
108
What is the equation to make NADH
(NAD+) reduced with (p+) and 2(e-)
109
What are the products of glycolysis
2 pyruvate
2 ATP
2 NADH
110
What happens to pyruvate at the start of KREBs
pyruvic dehydrogenase removes carboxyl => CO2
111
What does pyruvate become post pyruvic dehydrogenase
Acetyl
112
ACoA + oxaloacetate produces what?
citric acid + 2CO2
113
What do uncouplers do
Allow free flow of protons through membrane
114
What changes the shape of B subunit of ATP synthase
rotation of gamma shaft by PMF
115
How often does the shape of B subunit of ATP synthase change?
Every 120 deg
116
How are protiens carried into the mitochondria
Unfolding by HSPs through Transport Outer Membrane Proteins (TOMs)
117
Where do mictrotubs begin?
MTOC, radiate outward
118
What is the role of MicTubs
maintain cell shape, also movement and chromo movement
119
What are MicTubs composed of?
Alpha Beta dimers creating a protofilament strand
120
Which protofil dimer constituent hydrolyses its GTP?
Beta
121
Which is the busy end of the MicTub
Beta terminus (+)
122
How many protofils to a MicTub
13
123
What are 2 MTOCs
Centrsome and Basal Body of flagella/cilia
124
What is the centriole in the centrosome composed of
9 triplets of MicTubs
125
What does colechicine and colecemin do?
Depolymerizes Mic Tubs
126
What does gamma tubulin have to do with MicTub growth?
Starts MicTub growth @ MTOC binding alpha
127
What causes MicTubs to depoly naturally
Beta hydrolysing GTP
128
What are 3 MAPs (MicTub Assc. Proteins)
+TIP, MAP2, Tau
129
What is MAP2 involved in w/ Mic Tubs
Spacing
130
What is Tau implicated in in the brain
Alzheimers, amyloid tangles
131
What are the two MicTub motors and what are their endednesses
Kinesin (+), Dynein (-)
132
What are flagella/cilia internal structures called
Axonemes
133
What are axonemes composed of
9 doublets plus 2 MicTubs in center
134
What does the basal body look like
MTOC, 9 triplets of mictrotubles
135
What do the outer/inner dynein arms of axoneme require to move
Ca+ and ATP
136
What is the charge on the flagellar tip?
+
137
What are microfils composed of
Actin
138
What does g-actin need to become f-actin and what does f-actin resemble
Mg+ and ATP, double twisted strand of g-actin
139
What protein stims actin poly?
RACK
140
What protein stops actin poly
Rho
141
What binding site does the mysosin S1 head contain
ATP
142
What is unique about conventional myosin?
Bipolar filament
143
What is the subunit of the muscle fibre
myofibril
144
what is the subunit of the myofibril
the sarcomere
145
What does nebulin do
Acts as actin ruler in sarcomere
146
What does titin do
massive spring, myosin aligner and overstretch preventer
147
How is muscle contraction regulated
Tropomyosin lays on 7 actins
Troponin on Tropomyo
Ca+ causes troponin to change shape, moves tropomyo into groove on S1 head
Allows S1 to interact w/ actin
148
What are int fils good for?
Stable, good in nerve cells
149
How do int fils interact w/ other cysto skel elements
Plectin
150
Where do int fils polymerise
anywhere
151
What is the structureof int fils?
Dimer, tetramenr of those dimers, non polar
152
What does a tight junc look like and what is its purpose
honeycomb, prevents evaporation, movement of anytihng between cells
153
What are the 3 tight junction protiens
Occludin, Claudin and JAM
154
What is the purpose of desmosomes
Mechanical tolerance
155
What are the 2 cadherins in desmosomes
desmoglien and desmocollin
156
What is the role of Gap Juncs
Communcation
157
What is the gap junc protein
Connexin
158
What is the gao junc complex
A Connexon
159
How many connexins to a connexon
6
160
What is the nature of the gap junction channel
Hyphil
161
What causes connexons to close and how
Hi Ca+ presence rotates connexon, closing it
162
What is the role of Focal Adhesions
Attach cells to ECM
163
What are integrands found in
Focal adhesions and hemi desmosomes
164
What juncs use actin and what is the adherence between
Focal adhesions (cell-matrix)
165
What juncs use int fils and what is the adherence to
Hemi desmosomes (cell-matrix)
Desmosomes (cell-cell)
Both use keratin
166
How many times do G coupled protein receptors span the membrane
7
167
What is the G protein made of
G(alpha+beta+gamma) subunits
168
This receptor is also a GEF
G coupled protein receptor
169
What does GRK stand for
G coupled protein receptor kinase
170
What happens when Galpha-GTP binds the effector
ATP converted into cAMP
171
What prevents cAMP production due to Galpha-GTP at receptor
GRK
172
How does GRK operate
Phosphorylates GCPR, arrestin comes in
173
What can Arrestin trigger
calthrin coated vesicle formation to prevent further cAMP production
174
What are 5 2nd messengers and what do they activate
```
cAMP - ProkinA
cGMP - Prokin G
IP3 - Ca
Calcium - Prokin C
Diacylglycerol - Prokin C
```
175
How is the headgroup of PI cleaved?
Galpha-GTP stims phoslipC to cleave headgroup freeing IP3
176
What happens to the cleaved IP3 after released from PI
Recognized by smooth ER IP3 recep, releases Ca+ which stims prokinC
177
What happens when Ca+ is depleted from the cell
STIM in membrane aggragates, opening Orai1 Ca+ channels
178
What do Recp Tyrosine Kinase (RTK) recognize
Growth factors
179
What happens when RTK recognize a ligand
Dimerize, autotransphophorylate
180
What does Grb2 stand for
Growth factor receptor binding protein
181
What does Grb2 do?
Binds to kinase using SH2 domain
182
What binds to Grb2
Sos
183
What is Sos an example of
GEF
184
What does GAP stand for
GTPase Activating Protein
185
What starts the RAS cycle
Sos tickles to make RAS-GTP
186
What does RAS-GTP do?
Activates RAF via phosphorylation
187
What prevents RAS from cycling again?
GDP Dissociation Inhibitor
188
What does RAF(P) activate
MEK(P)
189
What does MEK(P) activate
ERK(P)
190
What does ERK(P) activate)
TF(P)
191
What phosphotase ends the MAP kinase pathway and how?
MKP1 cuts P from ERK(P)
192
What gives specificity to APC (anaphase promoting complex)
Acc. Proteins
193
What does APC-Cdc20 do
Destroys securin which was preventing separase from cleaving cohesin
194
What does APC-Cdh1 do
changes shape of mitotic cyclins
195
When is BRCA1/2 used
repairing DNA
196
What happens if BRCA1/2 fail
p53 leads cell to death
197
What are protooncogenes
Genes that could become cancer
