Cell Functioning Flashcards
1
Q
What does a Ligand-Receptor complex function as in Intracellular Signalling
A
Works as a transcription factor
2
Q
What causes the cell to proceed from the G2 phase into the M phase?
A
Phosphorylated Mitotic Substrates
3
Q
What type of adaptor is used the in MAPK pathway
A
SH2 adaptor
4
Q
Which amino acids have OH groups? What is the significance of this?
A
Serine, Tyrosine, Threonine This enable the amino acid to be phosphorylated
5
Q
What is the main mechanism used in Hydrophilic signalling
A
Protein kinases are activated resulting in: -Proteins with altered functions -Transcription factors activated
6
Q
What is PP2B also called? What does it do?
A
A phosphoserine and Phosphotheronine Phosphatase It is also called Calcineurin (binds Ca to get activated)
7
Q
What enables two BAX proteins to bind to each other? How does it do this?
A
BAD binds to BCL2, preventing it from binding to BAX, enabling BAX to bind to another
8
Q
What does the structure of PKA consist of
A
It is tetrameric: -2 regulatory subunits -2 catalytic subunits
9
Q
What is the role of Heparon Sulphate Proteoglycans
A
Bind growth factors such as FGF and PDGF restricting their action
10
Q
What are the variable properties that are manipulated in beads that are used in protein purification
A
Affinity for proteins (some won’t stick to beads)
Size-exclusion (some proteins will get trapped)
Ion-exchange (proteins with opposite charge will stick)
11
Q
What are autoimmune diseases caused by?
A
Not enough apoptosis of antibody producing B-cells after infection
12
Q
What two types of stem cells are there
A
embryonic stem cells adult stem cells
13
Q
What are selectins
A
Transmembrane proteins that bind carbohydrates on another cell’s surface
Used for cellular adhesion
14
Q
What is FGF and what role does it play
A
Growth Factor
Fibroblast
Growth Factor.
Crucial role in control of development
15
Q
How many amino acids does a kinase consist of
A
250 - 300 amino acids
16
Q
What two ligands are predominantly involved in both the PI3K and MAPK pathways
A
EGF (Epidermal Growth Factor)
PDGF (Platelet Derived Growth Factor).
17
Q
What is the role of Tetracylins
A
Blocks the A site of 30S ribosomal subunit of prokaryotes
18
Q
What are the products that exit the Golgi after protein processing
A
Secretory Vesicle
Membrane Vesicle
Lysosomal Vesicle
19
Q
What causes the hairpin loops from pri-miRNA to be cleaved off into separate ones? What does this form?
A
Drosha and DCGR8 Pre-miRNA
20
Q
What is the enzyme that aids peptide bond formation in Translation?
A
Peptidyl Transferase
21
Q
How does a Tyrosine Kinase Receptor get activated?
A
Dimerisation of catalytic sites
22
Q
What amino acid does CDK phosphorylate?
A
Serine and Threonine
23
Q
What three things does the Wnt pathway play an important role in?
A
Embryogenesis Proliferation of colorectal epithelia Bone formation
24
Q
Which direction does DNA replication occur
A
5’ —> 3’
25
What is SDS-PAGE used for
To separate and identify proteins
26
How long is one tRNA
75 nucleotides long
27
What is the adaptor used in the PI3K Pathway
SH2 adaptor
28
How can the E3 ligase subunit be changed to enable it to bind to a protein?
Phosphorylation
Ligand binding (causes allosteric transition)
Protein subunit addition (causes allosteric transition)
29
What is the main cause of the malfunctioning of the proteasome pathway?
Intracellular accumulation of misfolded proteins
30
Describe Inside-out activation of integrins
1: Talin is phosphorylated and activated 2: Activated talin binds to integrin and activates it
31
What shape is the G Protein coupled receptor? How many times does it span the membrane
Serpentine in shape Spans the membrane 7 times
32
What is the role of initiator caspase 8
It cleaves procaspases into effector caspases
33
What molecular interactions enable a tertiary protein structure to be formed
H bonds Ionic bonds Hydrophobic interaction VDW forces
34
What are two things that regulate gene expression
Chromatin structure
Signal transduction (environmental signals causing transcription factors to get activated)
35
What is the DISK made up of?
Death ligand
Death receptor
Adaptor Protein
Procaspase 8
36
What are the three groups that are cleaved off the rRNA strand, once is has been chemically modified
18s RNA (contributes to small ribosomal subunit - 40s) Contributes to Large Ribosomal subunit (60s) 5,85s RNA 28s RNA
37
What are two methods of Transformation in protein recombination
Electropolation (creates holes by current)
Chemicals (Ca salts + Heat Shock)
38
What constitutes the secondary level of protein structure
Backbone interaction (H bonds) making a structured chain
39
Name the three most common Hydrophobic first messengers
Steroid hormones
Thyroid hormones
Vitamins
40
What is a polyribosome
A mRNA molecule and two or more ribosomes that make up a complex
41
What form of energy is used in the elongation stage of Translation? What processes is it used for?
GTP is used as energy 1: When the tRNA attaches to the A site 2: When the ribosome is translocated to make space for another tRNA
42
What does quinobnes do? What are two examples?
antibiotic that inhibits topoisomerase Norfloxacin (prokaryotes only) Etoposide
43
What happens to RISK
The passenger strand is removed from complementary guide strand
44
In PAGE, how would one estimate the mass of a protein
For proteins of both known and unknown masses - Plotting Rf (relative migration distance) vs. log of its mass
45
What is the function of Axin and APC
Axin and APC both act as scaffold proteins in the degradation complex formed in the Wnt Pathway
46
Describe the process of cell migation
Makes use of transient adhesion
1: Protrusion of cell at leading edge (direction of movement) using actin filaments
2: Adhesion at leading ends using integrins
3: Deadhesion at trailing edge using inside-out signal to let go
47
What are Agiopoeitins and what important role do they play?
Growth factor Plays an important role in angiogenesis and cell adhesion of haematopoetic stem cells to their stem cell niche
48
What amino acid does Ca Calmoduin dependent kinase phosphorylate?
Serine and Threonine
49
What are the effector enzymes, 2nd messengers and kinase cascades associated with the Gq pathway?
Effector Enzyme - Phospholipase C
2nd messenger - DAG/IP3 Kinase
Cascade - Ca Calmodulin/PKC
50
What types of cellular junctions use Cadherins
Adherens Junction
Desmosomes
51
What two main regulators of cell proliferation
Proto-oncogenes
Growth inhibitors
52
What is the immediate result of activation of heterotrimeric G proteins
Activation of effector enzymes
53
What cleaves the head of the hairpin off pre-miRNA? What forms as a result?
Dicer and TRBP RISC RNA Induced silencing complex
54
What happens in the elongation stage of transcription
-- RNA polymerase form elongation (replication ) bubble
-- Nucleotides are added
-- RNA/DNA hybrids are formed
55
What is an indirectly labelled probe in FISH called
Hapten An antibody can be raised against it which makes it flourescent
56
What are ICAMs
Transient (unstable) cell-cell adhesion molecules that do not interact with the cytoskeleton of either cell
57
What two types of secondary protein structure are there
Alpha helix
Beta sheet
58
What do Aminoglycoside Antibiotics do
Modify ribosomal proteins
59
What causes a bacterial genome to become compacted? By how much is it compacted?
Loop domains Supercoiling within loop domains It is compacted 1000 fold
60
What binds to the promotor
RNA Polymerase
61
Which steps of the proteosome function require ATP
Unfolding protein Feeding protein in
62
What regulates the process of ribosomal subunits dissociating at the end of translation?
Releasing Factors (eRF's)
63
What are the effector enzymes, 2nd messengers and kinase cascades associated with the Gs pathway?
Effector Enzyme - Adenylate Cyclase
2nd messenger - cAMP
Kinase Cascade - PKA
64
What are the Purine Bases
G and A
65
What is the function of 2nd messengers
To activate kinases
66
Where do the sidechains of hydrophilic proteins point
Point to the centre
67
What is the function of the N terminal lobe of a kinase
Binds ATP
68
What is the role of Nuclear RNAi
Guide strand (of the mRNA/miRNA complex) directs Ago-2 to promotor regions of genes and Ago-2 methylates them, turning off the gene
69
What two molecules inhibit the elongation step of translation in bacteria
Macrolide
Peptidal Transferase Inhibitors
70
What is PAGE
Poly-acrylamide gel electrophoresis
71
What is one disease that can result from an inhibited Wnt pathway
Rheumatoid Arthritis
72
Describe the general pattern of digestive processes mediated by the lysosome
1: Protein taken into cell 2: Enters Early Endosome, forming a multivesicular body 3: The multivesicular body fuses membrane with a lysosome
73
What is anchorage dependent
When most cells need to be attached to ECM to proliferate and survive
74
What are the results of the MAPK Pathway
Altered proteins
Altered transcription factors
Proliferation due to G1 cyclins being produced (proto-oncogenes)
75
What is the role of p53
Acts as a tumour suppressor
76
What is one defining characteristic of the EGF Ligand
It gets anchored in the plasma membrane due to it containing a hydrophobic domain
77
What does SDS do to proteins
Coats them with a uniform negative charge - masks intrinsic charge. This uniform charge is proportion to the protein's molecular mass
78
What causes the polyribosome to be directed towards the ER?
The "Signal Sequence" on an already-formed part of synthesising DNA
79
What differentiates a peptide and a protein
A peptide is less than 30 amino acids long A protein is longer
80
Where do the sidechains of hydrophobic proteins point
Point to the outside
81
What kind of phosphate does a protein kinase add to target proteins? Where does it get this?
Adds a gamma phosphate from ATP
82
Where does folding of proteins take place?
In the ER Cisternae.
83
Where is the site of catalysis in a kinase? How is it regulated?
The cleft between each lobe in the catalytic domain is the site of catalysis It is regulated by an activation loop that is phosphorylated to activate kinase itself.
84
What is Rheumatoid arthritis
An autoimmune disease in which your joints become inflamed
85
What is an E3 ligase? What does it do?
E3 ligase is another name for E3 It transfers the ubiquitin from E2 onto the protein
86
What is one disease that can result from an overactive Wnt pathway
Ankylosing Spondylitis
87
What is the role of proteases in the immune system?
Cleaves bits of proteins into correct length to be displayed on MHC molecules
88
What does a BAX dimer do? Where is it located?
Secretes Cytochrome C Located in the mitochondrial membrane
89
What is a proprotein? What processes does it undergo?
A proprotein is an inactive protein. It is activated by the removal of a terminal amino group
90
What is the function of the aptosome
Activates Captase 9 (initiator Captase)
91
What adds a water molecule to the end of a polypeptide chain in translation?
Release Factor
92
What can unregulated RTK Signalling lead to?
Cancer Inflammatory diseases Diabetes
93
What is the formula for PCR
y=a\*2^x
y -- copy number
a -- starting number
x -- cycle number
94
Where is a Conserved Consensus Sequence found? What does it do?
Found in the promotor
Binds general transcription factors
Binds specific transcription factors
95
What is added to the 3' group on the acceptor arm of tRNA
CCA
96
What are released from when a phosphodiester bond forms DNA bonds
Pyrophosphate (PPi) and a Proton
97
How does beta-catenin act as a transcription factor
It binds to TCF
98
What molecule disrupts the elongation step of translation in all cells
Aminoacyl tRNA analogues
99
What is Lupus Erythematosus
An autoimmune disease in which one's own tissues are attacked
100
Wat happens in the termination stage of transcription
"transcription termination sequence" (polyadenylation signal) signals termination RNA is cleaved 10-30 BPs after RNA polymerase continues to transcribe
101
What directly activates the MAPK Cascade
RAS (Small monomeric G Protein) activated by GEF giving it an ATP
102
Fundamentally, what regulates apoptosis
Caspases
103
What are the three steps in PCR? What temperatures do they take place at?
Denaturisation (95 degrees) - forms single DNA strand Annealing/Hybridisation (55 degrees) - Primer anneals Extension/Elongation (72 degrees) - dNTPs added
104
How are integins connected to collagen in cell-ECM adhesion
Laminin connects Integrins to Collage
105
What happens to the 3' end of mRNA
polyadenylated
106
How does one perform 2D gel electrophoresis
1: do isoelectric focusing in a tube gel to separate according to charge
2: perform SDS-PAGE on this tube gel to separate according to mass
107
What is isoelectric focusing (IEF)
When you use a gel that has a pH gradient to separate proteins based on their pH
108
What are the types of Cytoplasmic Tyrosine Kinases
SRC
109
How is the degradation complex prevented from forming when the Wnt ligand is attached to the Frizzled membrane receptor
Axin (scaffold protein) binds to LRP GSK (kinase) is inhibited by Frizzled
110
What are the four diseases that result from too much apoptosis of body cells
Alzheimer
Parkinsons L
oss of CD4 cells in HIV/AIDS
Sepsis (apoptosis of immune regulator cells & GIT epithelial cells)
111
What regulates the process of translocation during Translation?
Eukaryotic Elongation Factors (EEF's)
112
What binds to the active site of a protein kinase
Protein & ATP
113
What is the core component of the proteasome made of
Catalytic (proteolytic) sites
114
What part of the histone can be enzymatically modified
N-terminal tails
115
What is adjacent to integrins in the cell-ECM adhesion structure
Collagen XVII
116
What is Ubiquitin activating enzyme? What does it do?
E1 Forms a bond with ubiquitin
117
What two types of hydrophobic (non-polar) amino acids are ther
Aliphathic (chain) Aromatic (ring)
118
What causes phosphorylation of Mitotic Substrates
Complexes made of:
- Mitotic Cyclin
- CDK 1
119
What splits the plasmid's DNA or the desired gene's DNA in protein recombination?
Restriction Enzyme
120
What is intrinsic GTPase activity
When cells convert GTP to GDP to switch themselves off. Used in G proteins
121
What is PP2B also called? What does it do?
A phosphoserine and Phosphotheronine Phosphatase It is also called Calcineurin (binds Ca to get activated)
122
In what types of kinases is the regulatory section part of the same chain as the catalytic domain?
Ca Calmodulin Kinase SRC Tyrosine Kinase
123
In which stage of the cell cycle is the signal recieved to replicate
G1
124
What happens after protein folding in the processing of newly-synthesised proteins?
The protein is enclosed in transport vesicles and budded off from the ER. It then travels to the Golgi for further processing
125
How do effector captases get activated
Captase 9 cleaves Procaspases into Effector Caspases
126
What are two RTK receptors used in both the MAPK and PI3K Pathways
EGFR
PDGFR
127
What is the main example of a membrane receptor without associated kinase activity
G protein coupled receptor
128
What membrane receptor do 50% of modern drugs tarted
G Protein Coupled Receptor
129
What are the variable properties that are manipulated in beads that are used in protein purification
Affinity for proteins (some won't stick to beads) Size-exclusion (some proteins will get trapped) Ion-exchange (proteins with opposite charge will stick)
130
If you can't see a protein after SDS-PAGE, what should you do
use a Silver Stain or Coomassie Stain
131
What is VEGF and what role does it play
Growth factor Vascular Endothelial Growth Factor. It plays an important role in agiogenesis
132
What are the funcations of the regulatory caps on each end of the proteasome
Recognises proteins
Unfolds proteins
Feeds proteins in
133
How does Ca Calmodulin dependent kinase get activated
When calmodulin with attached Ca binds to regulatory domain
134
Where does the processing of proteins take place?
ER
135
What do viruses do with miRNA
Inhibit cellular factors involved in immunity Downregulate expression of viral proteins
136
What are the steps involved in FISH
1: Probe and sample prepared
2: Probe labelled
3: denaturing
4: Probe hyybridised to sample
5: sample imaged
137
Which end of the protein does the joining of cadherins occurs
N-terminal end
138
What are the specific protein properties that are used for protein purification?
Size
Charge
Hydrophobicity
Biorecognition
139
What is the function of the C terminal lobe of a kinase
Binds substrate (protein)
140
What causes phosphorylation of G1 substrates
Complexes made of: - G1 Cyclin - CDK 2
141
Which molecular family are ICAMs a part of
Immunoglobin superfamily
142
What is another name for an enhancer region
Regulatory sequence
143
What is the name of the domain in an adaptor protein that links phosphorylated tyrosine amino acids
SH2
144
What are the four phases of the cell cycle
M
G1
S
G2
145
What keeps adult stem cells from differentiating
Intrinsic cell signals Stem cell niche - gives signals to remain as it
146
Describe the outside-in activation of integrins
1: Ligands bind to extravellular integrin domain This can result in: 1: The activation of pathways ---- such as MAPK 2: These ligands can phosphorylate nearby proteins in cell membrane to create docking sites for other signalling proteins
147
What makes up the degradation complex in the Wnt pathway
Axin
GSK
APC
Beta-catenin
148
What are the three sites on a ribosome?
E - Exit P - Peptide Bond formation A - Arrive
149
What is the receptor-related protein for that of Frizzled
LRP
150
What are the four arms of a tRNA
Acceptor Arm (top D arm (right) Anticodon Arm (bottom T, psudouridine, C arm (left)
151
What is the initiation codon at the transcription start site
ATG
152
What are the defining characteristics of RTK receptors
1: Need to be dimerised 2: Made of groups of Tyrosine Amino Acids
153
What do Dipheria Toxins do
modify the EEF-2 in all mammalian cells - Inhibiting translation
154
What are the two regulatory domains of an SRC Tyrosine Kinase called?
SH2 & SH3
155
What is one defining characteristic of PDGF
It sometimes needs to be cleaved by proteases in ECM to become activated
156
What does malfunctioning of the proteasome pathway lead to?
Degenerative diseases such as Alzheimers and Parkinsons Disease
157
What do you see if fish is imaged during metaphase
Chromosomes
158
What is the direct role of PI3K
Phosphorylates PIP2 to turn it into PIP3
159
Which part of the DNA strand holds nucleosomes together
Linker DNA
160
Where does glycosylation happen?
ER Golgi Cytoplasm
161
What are four methods of Transfection in protein recombination
Electropolation (creates holes by current) Chemicals (Ca salts + Lipids) Microinjection Opticalation
162
What is a Hormone Response Element
Short sequence of DNA within promotor of a gene able to bind a specific hormone receptor complex and regulate transcription
163
What makes holes in the mitochondrial membrane enabling cytochrome C to be released? Which secretions do this?
Cyototoxic CD8 T cell & NK Cell Release: - Granzymes - Perforin
164
How many domains does an adaptor protein consist of
two or three
165
What does rigampicin do
antibiotic inhibits a subunit of bacterial RNA polymerase from creasting first phosphodiester bond
166
What is the anti-cancer drug that uses the proteasome pathway to operate? What does it do?
Bortezomib Blocks the proteasome - resulting in increased apoptosis of cancer cells
167
What are the two lobes that the catalytic domain of a kinase consists of
N terminal lobe C terminal lobe
168
Where are the checkpoints found in the cell cycle
G1 and G2
169
What do you see if fish is imaged during interphase
nuclei
170
What are the two main anchor proteins in the inside of the cell used in the functioning of a Caderin
p-120 catenin beta-catenin
171
What happens to Cytochrome C once it is released into the cytoplasm
It joins with APAF and Procaspase 9 to form an Aptosome
172
What is pemiphigus
When there are antibodies attached to cadherins of the skin
173
What are the sequences for a stop codon
TAA/TAG/TGA
174
What are the two words used when introducing rDNA in Bacteria and Eukaryotes respectively
Transformation - Bacteria
Transfection - Eukaryotes
175
How far upstream from the transcription start site is the promotor
27 bases upstream
176
What are the two ends of a hydrophilic (polar) amino acid
Hydroxyl - positive
Amide - negative
177
Which strand of DNA is not transcribed? What is it called?
Coding Strand Sense strand
178
What are the types of Cytoplasmic Serine & Theonine Kinases
MAPK
AKT
PKA
PKC
179
How many Restriction Endonuclease sites does an ideal cloning vector have in gene recombination
One
180
What happens in initiation of Translation? What regulates it?
5' end of mRNA binds to small ribosomal subunit
Large ribosomal subunit attaches to this
Binding of the Large ribosomal subunit is regulated by Eukaryotic Initiation Factors (EIF's)
181
What type of amino acid can be phosphorylated?
Any amino acid containing a hydroxyl (OH)
182
How many different alpha chains and beta chins are involved in integrins
18 alpha chains 8 beta chains
183
What is the first amino acid used in Translation?
Met
184
What is a transcription initiator complex
Activators (bind to enhancer) and General transcription factors which enable transcription to happen
185
What are the main therapies against the RTK fmaily
Trastuzumab: Herceptin (Anti-HER2)
Gefitinib (anti-EGFR)
186
How many base pairs of DNA can a histone wrap
147
187
What is a motif? What can it also be called?
A specific short amino acid sequence. Also called a Consensus Sequence
188
What are the types of Receptor Tyrosine Kinases
EGFR JAK
189
What is autophagy used for
Used to break down things INSIDE the cell
190
What can be used as plasmids in protein recombination
Plasmids (Extrachromosomal molecules in bacteria) Bacteriophages (viruses that infect bacteria) Cosmids (specialised DNA plasmids with sequences called cos sites)
191
How does PKA get activated
cAMP binds to a regulatory subunit
192
What is the role of effector captases
Cause celllular proteolysis (protein degradation) which in turn cause cellular apoptosis
193
What processes occur at part of Termination of Translation?
1: Stop codon appears in A site
2: Water molecule added to end of polypeptide chain
3: Ribosome subunits dissociate
194
What determines a cell's fate
1: The receptor that a cell has 2: The growth factors that it encounters
195
What type of intracellular filaments are adherens junctions involved with
actin filaments
196
What is the polycistronic (many) hairpin loop chain called in RNA interference
Pri-miRNA
197
How do small monomeric G proteins activate kinases? Where do they get their energy to do this?
Bind GEF (Gaunine nucleotide exchange factor) In the process, use GTP.
198
What is the role of PIP3
Binds AKT (using it's PH domain) which enables other enzymes to phosphorylate AKT
199
What happens to AKT once it is phosphorylated
Acts as a kinase and phosphorylates proteins (NOT TRANSCRIPTION FACTORS) involved in survival and proliferation
200
What is the DNA sequence of a splice site
AG/...exon.../GT
201
What is the role of intermediate filaments
Provide mechanical strength for the cell
202
What is used as a solvent that proteins can run through in the process of protein purification
Beads with specific properties
203
What is PP2A
A Phosphoserine and Phosphotheronine Phosphatase. It reverses phosphorylation in signalling pathways activated by growth factors
204
What is the collective term for a base and sugar
nucleoside
205
What is the name of the process whereby sugar groups are added to a newly-synthesised protein
Glycosylation
206
What are some examples of adult stem cells
Intestinal villus Muscle satellite cell Hair follicle Haematopoeitic stem cells
207
What is the role of Actin filaments
Determine the shape of the cell's surface
Responsible for locomotion
208
In what types of kinases is the regulatory section part of a different protein chain as the catalytic domain
PKA CDK
209
Describe the process of Microautophagy
When endogenous proteins (inside the cell) get endocytosed into lysosome of cell
210
What is the primary role of the enhancer
To control the rate of the promotor activation
211
What is pemphigoid
When there are antibodies attached to components of the hemidesmosome
212
What causes the cell to proceed from the G1 phase into the S phase?
Phosphorylated G1 substrates
213
Which two proteins of the Wnt pathway are scaffold proteins
Axin and APC
214
How is Beta-catenin degraded when there is no ligand attached to the Frizzled membrane receptor protein
GSK causes beta-catenin to become phosphorylated which causes it to be ubiquinated by E3 Ligase
215
What makes it possible for there to be many more mRNAs than genes?
Alternative splicing - many different ways an mRNA can be spliced
216
What does RNA Polymerase attach to
Transcription factors at the promotor
217
What is one disease that can result from an overactive Wnt pathway
Ankylosing Spondylitis
218
What is the active form of the G Protein? Vice versa?
Active = GTP on alpha subunit Inactive = GDP on alpha subunit
219
In PAGE, how is the migration distance of the protein related to it's mass
The migration distance is negatively proportional to the log of its mass
220
Describe the process of Macroautophagy
1: Phagopore surrounds large cellular components of cell 2: Phagopore closes to form Autophagosome 3: Autophagosome fuses membrane with lysosome
221
What is the significance of the restriction point? Where is it found in the cell cycle?
Once past restriction point, cells are committed to divide Restriction point happens late in the G1 phase
222
When do proteins stop moving in IEF
At their Isoelectric point. This is when the Isoelectric Charge is equal to their pH
223
What is the pH gradient in IEF caused by?
Presences of ampholytes in IEF gel causes pH gradient
224
What process regulates degradation of proteins in the proteasome?
Polyubiquination
225
What is the sequence of amino acids that integrins always bind to
RGD: - Arganine - Glycine - Aspartic Acid
226
What is the chemical modification that rRNA undergoes to become a ribosome
Methy groups added Pseudouridine added
227
Which are the signalling pathways that are involved with regulating growth factors
Tyrosine Kinase Receptor Pathways (MAPK, PI3-K)
228
What is a directly labelled probe in fish called
fluorophore
229
What constitutes the tertiary level of protein structure
3D structure of a chain
230
What happens to Procaspase 8 when the death receptors are active
The activated death receptors cause Procaspase 8 to be cleaved into Initiator Caspase 8
231
What are transient amplification cells?
Cells that give rise to other differentiating cells (like stem cells) but that differentiate themselves later on into the desired tissue
232
How does phosphorylation of a protein result in conformational changes
Phosphorylation adds two negative charges which changes the protein's structure
233
Which end of the Amino Acid is added to tRNA? What regulates this?
COOH group - added to 3' end tRNA synthases
234
What happpens when a scaffold protein is phosphorylated?
Many different proteins with SH2 domains are recruited
235
Which is the length-determining phase of the cell cycle
G1
236
What causes translation suppression of mRNA
When the miRNA does not match perfectly
237
What happens to the 5' end of an mRNA
Capped with 7-methyguanosinetriphosphate
238
What causes degradation of mRNA
When the miRNA matches perfectly
239
What happens in the Initiation stage of transcription
-- Helicase, a subunit of RNA Polymerase, unwinds DNA
-- First 8/9 nucleotides are linked
-- Transcription factors and RNA polymerase are released from the promotor region and RNA polymerase moves along
240
How is the sample prepared during FISH
Cells are fixed (formaldehyde) and Permeabilised (detergents)
241
What are the four required features of a cloning vector in protein recombination
1: Appropriate origin of replication 2: Marker genes 3: Restriction endonuclease (ER) sites 4: Promotors
242
In which way does one label condons or anticodons?
3' to 5'
243
What determines the speed of migration of proteins in PAGE?
Molecular weight
244
What amino acid does PKA phosphorylate
Serine and Threonine
245
What is the function of effector enzymes
To produce second messengers (e.g. cAMP, IP3)
246
How is an SRC Tyrosine Kinase activated
Dephosphorlatioon
247
How is the probe prepared during FISH
DNase I - Introduces Nicks into probe DNA Polymerase - Fills in nicks with modified dNTP
248
What does Actinomycin D do
antibiotic Inserts between two GC pairs in DNA (prokaryotic and eukaryotic)
249
What do scaffold proteins do
Bind other proteins to bring them into a complex
250
What is Ubiquitin-conjugating enzyme? What does it do?
E2 Recieves ubiqutin from E1
251
What are the Pyrimidine Bases
C, T and U
252
What kinase is a cytokine receptor associated with
JAK (tyrosine kinase) that phosphorylates the tail-end motif sequence containing Tryosine
253
What are the two functions of adaptor proteins
Link proteins together Pass signals on
254
What are the three classes of RNA Polymerase
Type 1 - makes rRNA
Type 2 - makes mRNA
Type 3 - makes tRNA
255
What is used to prepare for viewing the product of PCR
Agarose Gel Electrophoresis
256
What are the sequences found in the promotor region
TATA CAAT
257
What part of the Golgi does a transport vesicle containing a newly-synthesised strand of protein attach to?
The cis face
258
What are the types of Receptor Serine & Theonine Kinases
Transform growth factor beta
TGFBRI
TGFBRII
259
What is the function of GSK
Kinase that acts on beta-catenin in the degradation complex of the Wnt Pathway
260
What process regulates protein sorting (making sure proteins get transported to correct location)
Monoubiquination
261
Which part of DNA is transcribed? What is it called?
Template Strand Antisense Strand 3' -----\> 5'
262
In PAGE, what does a lower concentration of acrylamide result in?
Bigger pores
263
What is the role of microtubules
Determine position of organelles
Directs intracellular transport
264
What is the most common cancer as a result of not enough apoptosis
Lymphoma
265
What type of intracellular filaments are desmosomes involved with
Intermediate filaments
266
What type of polymerase is used in PCR
Taq Polymerase
267
Which molecules are involved with the folding of proteins
hsp60 protein-like complex GroES Cap
268
What constitutes the primary level of protein structure
Peptide bonds between amino acids, making a chain
269
What prevents two BAX proteins binding to each other? How does it do this?
BAX binds to BCL2, preventing it from binding to another BAX
270
In the G Protein, which subunit dissociates and regulates the target protein
Alpha subunit
271
Describe the structure of a kinase
A polypeptide chain that has -Catalytic domain (with active site) -Regulatory domain A polypeptide chain with a regulatory subunit
272
What two processes regulate chromatin organisation
methylation and acetylation
273
Which molecule undergoes proofreading activity? What is this activity called?
DNA Polymerase Exonuclease activity
274
What is the function of reverse transcriptase? What is it used for?
Reverse transcribes mRNA into DNA. It is used to take an mRNA molecule and change it into it's corresponding DNA strand to insert it into a recombinant plasmid
