Test Three Flashcards
1
Q
Chemical processes must stay isolated through
A
Membrane-enclosed compartments
2
Q
How many compartments in prokaryotic cells
A
One compartment
3
Q
Eukaryotic cells contain
A
Many organelles with specialized functions
4
Q
What is the structure of the nucleus
A
Double membraned nuclear envelope with nuclear pores
5
Q
Function of nuclear pores
A
Allow RNA to leave cell and bring raw materials into the cell
6
Q
What is the structure of the ER
A
Flattened sacs
7
Q
Where is the location of the ER
A
Extension of nuclear envelope
8
Q
Rough ER function
A
Protein production
9
Q
Smooth ER function
A
Production of lipids
10
Q
What organelle is similar to ER
A
Sarcoplasmic reticulum
11
Q
Function of sarcoplasmic reticulum
A
Stores calcium
12
Q
Function of golgi
A
Modified proteins and lipids for transport (modify and package)
13
Q
Structure of golgi
A
Contains cisternae that stacks of compartments
14
Q
Function of lysosomes
A
Breakdown endocytosed molecules such as macromolecules and old, nonfunctioning organelles
15
Q
Function of peroxisomes
A
Breakdown toxins to the cell and breakdown lipids and uses oxidative reaction
16
Q
Function of endosomes
A
Sort endocytosed material coming into cell
17
Q
Structure of mitochondria and chloroplasts
A
Double membrane
18
Q
Function of chloroplasts
A
ATP production through photosynthesis
19
Q
Function of mitochondria
A
ATP production through oxidative phosphorylation
20
Q
Function of cytoskeleton
A
Hold organelles in place, moving vesicles through the cell, provide structure and support
21
Q
What are the two theories of organelle evolution theories
A
Invagination and eukaryotic engulfing
22
Q
When the cell divides what else divides
A
Organelles such as the nuclear envelope, ER and golgi
23
Q
What is invagination
A
Plasma membrane enfolded to surround and protect the DNA
24
Q
What is engulfing
A
Organelles such as a mitochondria were engulfed by an ancient eukaryotic cell and once inside split into two different mitochondria organelles
25
New lipids come from
Smooth ER
26
During cell division what organs divide as well
Nuclear envelope, ER and golgi
27
What happens to proteins in the cell
Formed constantly, sorted and delivered
28
Why are proteins formed constantly
Need for general maintenance
29
What is a sorting signal
Amino acid sequence that is part of protein telling where to go
30
Where are some end destinations of proteins
Mitochondria, chloroplasts, peroxisomes
31
What are the three types of protein transport
Gated, transmembrane and vesicular
32
Gated transport occurs only through
Nucleus
33
Where is nucleus does proteins go through for gated transport
Nuclear pores
34
Describe type of molecules that go through gated transport
Specific for larger molecules, specific sequence in protein, folded proteins only
35
Transmembrane transport is what for proteins
Protein translocators
36
What is protein translocators
Locate proteins across the membrane
37
Where are transmembrane transports found
ER, mitochondria, chloroplasts, and peroxisomes
38
Transmembrane transport requires
Unfolding of the protein
39
Vesicular transport contains vesicles that bud from
ER and take part of membrane with them
40
Where do vesicles in vesicular transport go
Go to golgi, lysosome, or cell membrane and fuse with their membrane
41
Vesicles in vesicular transport carry what
Deliver lipids and proteins
42
What are signal sequences
Sorting signals of 15 to 60 amino acids that get the protein where it needs to go
43
Signal sequences are cleaved by
Signal peptidases
44
What happens to protein when signal sequence is cleaved
Protein can now fold correctly once at its new location
45
What are signal patches
Sorting signal is the 3D conformation that is recognized by sorting receptors
46
What in nucleus regulates what is going in and out
Inner membrane that contains binding sites
47
The outer nuclear membrane is similar to what organelle
ER
48
Function of outer nuclear membrane
Structural support
49
Outer nuclear membrane is continuous with what
ER
50
Nuclear pore transport goes through
Nucleoporins
51
What is the movement of nuclear pore transport
Both in and out
52
What goes in nucleoporins
Proteins
53
What goes out of nucleoporins
RNA and ribosome subunits
54
What channels in nucleus allow for small water soluble molecules to pass through
Water channels
55
Larger molecules need to have what to be directed into the nucleus in nuclear transport
Nuclear localizing signal (NLS)
56
What is a nuclear transport receptor
Mediate interaction between cytosol located on the nuclear protein and nuclear pore
57
How do nuclear transport receptors work
Receptors bind signal on the protein and move through the pore of the nucleus
58
What is needed for nuclear transport receptor to work
GTP hydrolysis
59
Proteins being transported into the mitochondria have to be
Unfolded
60
What is in the mitochondria to help refold the protein
Chaperones
61
Lipids bound for organelles are transported how
Vesicular transport
62
Proteins transported to ER need to be
Unfolded
63
Proteins leave the ER in what
Transport vesicles
64
What types of proteins can enter into ER
Water soluble proteins
65
What proteins are membrane bound with ER transmembrane transport
Potential transmembrane proteins
66
What directs the protein to the ER
ER signal sequences
67
Can proteins be partially formed before they cross the ER membrane
Yes
68
What are the three types of ribosomes in the ER
Membrane bound ribosomes, free ribosomes and polyribosomes
69
Membrane bound ribosomes go where in the ER
Attached to the cytosolic side of the ER
70
Where are free ribosomes in the ER
Unattached, they will make proteins from other nuclear DNA that’s out in the cytosol
71
What are the polyribosomes in the ER
1 long mRNA with the ribosomes bound to it
72
What are the components required to direct a protein into the ER
Signal recognition particle (SRP) and SRP receptor
73
What a re signal recognition particle (SRP)
Bind to signal sequence of protein in the cytosol
74
Where is the SRP receptor located for protein transport into ER
Membrane bound on ER
75
Binding of SRP to protein results in
Slowing of synthesis
76
Does synthesis of protein occur after SRP binds to it
Yes
77
What cleaves an SRP
Signal peptidases
78
What is transmembrane transport into ER membrane
The protein remains partially in the membrane
79
What is a single pass protein
Protein that has only one portion spanning the membrane
80
What occurs during single pass protein transport into ER membrane
Signal sequence assists the protein getting into membrane till it hits the stop transfer sequence (hydrophobic A.A.) and will stop the protein from entering any further
81
What is a multi pass protein
Protein the spans the membrane multiple times
82
How does a multi-pass protein transport into the ER membrane
Contains internal signal sequence (start sequence) in the middle of the protein then contains several stop-signal sequences
83
What is vesicular transport
Protein goes from ER to Golgi apparatus through transport vesicles
84
In order for protein to leave ER what must happen
It must be protected/ stabilized with chemical modifications such as carbohydrates added or disulfide bonds added
85
Secretory pathway of vesicular transport AKA
Exocytosis
86
What is secretory pathway of vesicular transport
Transport proteins to cell surface or lysosomes
87
What is endocytic pathway of vesicular transport
It’s an internal pathway that uses selective transport, taking something from outside in
88
Coated vesicles have what type of coat
Protein
89
Vesicle coat functions
Forms the membrane into a bud and captures selected molecules, helps develop membrane of vesicle, select molecule interested in carrying. NOT USED FOR PROTECTION!
90
What is the structure of clathrin-coated vesicles
Triskelion
91
Clathrin coated vesicles move from
Golgi outward or plasma membrane inward
92
If a clathrin-coated vesicle is being created, what is needed
Dynamin to help form a ring that contracts and helps pinch off the vesicle from membrane
93
Function of adaptin
Mediate interaction between clathrin, select molecules for transport, secure clathrin to plasma membrane
94
What are the two types of adaptin types
Bind cargo receptors in plasma membrane to pull things in or bind cargo receptors in Golgi apparatus to pull things out
95
COP coated vesicles go to
Golgi and ER
96
In vesicle docking, transport vesicles have what surface marker
Rab
97
What is Rab
Surface marker of transport vesicles directing vesicle that are recognized by and binds to tether proteins
98
What are tether proteins
Help dock vesicle by being the receptor for surface markers, grab hold of Rab
99
What are the two types of SNAREs
V-SNARE( vesicle) and t-SNARE (target)
100
What is exocytosis
Proteins exit the cell and this specific and has directed routes
101
How do SNARE’s interact
Remove water from vesicle to allow for merging and draw membranes together through chemically intertwined snares
102
What are the two protein modifications in the ER
Formation of disulfide bonds and glycosylation
103
The formation of disulfide bonds on proteins in the ER help what
Stabilize proteins and protect them
104
Where do disulfide bonds occur in proteins in ER modification
At cysteine residues
105
What occurs during glycosylation of proteins in ER modifications
Oligosaccharides side chains attach to proteins and become glycoproteins
106
What is the function of oligosaccharides in ER modifications
Protects from degredation outside of cell, chaperoning for proper folding, directing to correct location, assisting in INTERCELLULAR recognition between cells.
107
How does oligosaccharide processing occur in ER modification
Add 14 sugars at a time using oligosaccharide transferase and dolichol to anchor the sugar
108
What occurs when protein is leaving the ER
Transport vesicle begins to bud, proteins have to be folded correctly and if not chaperones will keep protein in ER.
109
What occurs with cystic fibrosis mutation and protein exiting the ER
Chaperones wont let the protein out due to a problem with the chloride transport protein
110
What is the unfolded protein response in the ER
When the ER and chaperones become overwhelmed it triggers a response causing the ER to grow and more chaperones grow but the chaperones can not keep up and causes apoptosis
111
What is an example of unfolded protein response in the ER
Diabetes
112
Vesicles from the ER enter where in the golgi
Cis side
113
What happens if proteins from the ER have ER retention signal
Receptors on the Cis of golgi will see signal and send the protein back to the ER
114
What occurs when the protein is in the golgi
Oligosaccharide removal and/or addition
115
What are the two exocytosis pathways
Constitutive and regulated
116
What is constitutive exocytosis pathway
Default pathway that has no direction specificity
117
What is regulated exocytosis pathway
Secretion that is specific loading of molecules and specific transport
118
Where are the destinations for the proteins in exocytosis
Adhesion to cell surface, incorporation into extracellular matrix, diffusion into extracellular fluid
119
What is not needed for constitutive pathway
No signal sequence necessary
120
What are the secretory products in regulated exocytosis pathway
Hormones, mucus, digestive enzymes, neurotransmitters
121
Describe secretory vesicles of regulated exocytosis pathway
Packaged with only one type of molecule
122
Where are the vesicles located in regulated exocytosis pathway
Near the plasma membrane but will wait for signal to unload
123
How does the vesicle prepare itself
Gets concentration of aggregated proteins for export and vesicle pinches off
124
The fusion of membranes is a
Temporary membrane combination
125
What are the two types of endocytosis
Pinocytosis and phagocytosis
126
What is pinocytosis
Cellular drinking, taking in fluids but also small molecules
127
What is phagocytosis
Cellular eating, taking in cellular debris, microorganisms
128
What endocytosis do all cells use
Pinocytosis
129
What are phagocytic cells
Macrophages and neutrophils
130
What is the target material of phagocytes
Dead RBC’s
131
Function of phagocytes
Digest phagocytosed materials and destroying it with lysosomes
132
What is the phagocytic process
Materials bind to phagocytic cell through specific surface receptors then the pseudopods extend from plasma membrane and pull pathogen into cell then the phagosome and lysosome fuse and digestion occurs
133
What are the two surface receptors of phagocytes
Antibody based receptors (specific) and receptors specific for common proteins (general)
134
What pathogen escapes phagocytic process
Tuberculosis bc want to be eaten by macrophage and prevent phagosome and lysosome from fusing
135
What materials are engulfed in pinocytosis
Lipids and fluids
136
What occurs to the plasma membrane components when engulfed through pinocytosis
Returned to cell
137
Pinocytosis macrophages ingest how much fluid volume in one hour
25%
138
What is located in smaller vesicle of pinocytosis cell vesicle goes to
Endosomes
139
Function of endosomes
Where sorting takes place, determine where things are going to
140
What makes pinocytosis specific
When clathrin coated pits are added
141
Example of pinocytosis
Cholesterol is taken up specifically by bringing cholesterol into cell then digested by lysosome. If LDL receptor is missing, then there is a build up then you have cholesterol building up in vessels and cant be digested
142
What are examples of misuse of endocytic pathways
HIV and influenza
143
What is the structure of endosomes
Contain ends that are called early and late which contains a network of tubes and vesicles
144
What happens to the receptors on the endosome
Recycled or degraded
145
How do endosomes sort
Transcytosis
146
What is transcytosis
Moving the loaded receptor with molecule to another side of the membrane
147
Structure of lysosome
Stacks of very strong digestive enzymes
148
What enzyme is used in lysosomal digestion
Acid hydrolases
149
What is the lysosomal environment and how maintained
Acidic for better function of enzymes and is maintained by H+ pump
150
What occurs after lysosomal digestion
Membrane proteins allow particles to be exported
151
What is the inner surface of lysosomal membrane like
Highly glycosylated
152
What occurs to vesicles that are heading to lysosome
Tagged with sugar called M6P
153
Purpose of M6P tag on vesicles
Keep them from binding to everyone else
154
What are autophagosomes
Engulf non-functional organelles and form a vesicle from own membrane and deliver to lysosomes
155
What is a signal transduction
Sending information into cells in language they understand
156
What are signaling molecules
Neurotransmitters, one receptor and another coming together
157
An intracellular response causes
Cell signaling
158
What are the five types of signaling
Endocrine, paracrine, neuronal, contact and autocrine
159
Endocrine signaling goes where
Whole body signaling
160
What are the signaling molecules in endocrine signaling
Hormones secreted in bloodstream
161
What are the signaling cells in the endocrine signaling
Endocrine cells
162
Example of endocrine signaling
Pancreas secreting insulin
163
Paracrine signaling location
Local diffusion in extracellular matrix
164
What are the signaling molecules in paracrine signaling
Local mediators, cytokines
165
What are the signaling cells in paracrine signaling
Immune cells or injured cells
166
Example of paracrine signaling
Inflammation and wound healing
167
Location of neuronal signaling
CNS
168
Signaling molecules of neuronal signaling
Neurotransmitters
169
Signaling cells of neuronal signaling
Neurons
170
Example of neuronal signaling
Crossing synapses to target tissues
171
Location of contact dependent signaling
Between cells, intimate, short range
172
Signaling molecules of contact dependent signaling
Receptor binding to ligand
173
Signaling cells of contact dependent signaling
Any cell because all have receptors
174
Example of contact dependent signaling
Embryonic development
175
What is autocrine signaling
Cell will signal to itself
176
Cell signaling is a selective response and how
Choosing the signals that apply since they are hit from all sides by different signals
177
What limit what signals the cell receives
Cellular receptors
178
Cellular receptors have what type of response and due to what
Complex response and due to result of receptor binding
179
What is an example of a complex response with cellular receptors
Acetylcholine binding to pacemaker to slow down rate or salivary gland causing secretion
180
What are simultaneous receptor stimulation
Collection of receptors, intracellular signaling yields larger cellular response
181
How does it take for multiple receptors simultaneously
Longer response due to cell dividing, differentiating or programmed cell death
182
Single receptor can include what in the signal
Change in cell shape, movement, metabolism or gene expression. This is fast
183
Large molecules rely on what type of receptor
Extracellular receptor
184
Small molecules (hydrophobic) can pass directly through membrane and affect what
Enzymes by turning them on or off
185
Small molecules that pass directly through the membrane bind to what receptor
Intracellular
186
Example of small hydrophobic molecule that passes through membrane
Hormones
187
Hormones target what receptors
Intracellular receptors
188
Examples of hormones
Cortisol, estradiol, testosterone, and thyroxine
189
When hormones bind to intracellular receptors what happens to them
Conformational change occurs which changes in gene expression
190
Is nitric oxide a hormone
No
191
What is the half life of NO
5 to 10 seconds before converted to nitrate
192
How does NO work
Enters cell directly to activate intracellular enzymes
193
Example of NO
Endothelial cells NO to relax blood vessels when they are constricted
194
What enzyme does NO activate
Guanylyl Cyclase to form GMP
195
What is in a signaling cascade
Primary transduction step, intracellular signal and signaling cascade
196
What is the primary transduction step
First binding of ligand to receptor
197
Bind of a ligand to receptor in signaling cascade causes
Intracellular signal leading to multiple intracellular signals (cascade)
198
What are the steps in functions of signaling cascades
Transforming external signal into intracellular molecule for signaling, relaying signal to cellular response, amplify signal, distributing signal, integration of signal (lead to other pathways)
199
What are the two types of receptors for molecular switch
G protein coupled receptors and enzyme receptors
200
How do molecular switches work
Molecular switches are activated when signaled and then turn on other protein and then turn off in response to another signal
201
molecular switches are
Chemical transducers or signaling messengers
202
What are the two types a of molecular switches
Phosphorylation activated and GTP binding activated
203
What is phosphorylation activated and inactivated switches
Kinase adds phosphate to turn on and removes to turn off
204
What kinases are used in phosphorylation activation switches
Serine threonine kinase and tyrosine kinase
205
GTP binding activated switch works how
Add entire GTP and is activated, loses phosphate to GDP and becomes inactivate
206
What are the three classes of receptors
Ion channel coupled, G protein coupled, and enzyme coupled
207
What are ion channel coupled receptors
Ions bind to channels, open channels and ions enter
208
What are G protein coupled receptors
Ligand bind to receptor, activates G protein, G protein can then activate enzyme
209
How do enzyme coupled receptors work
Ligand binds them to enzyme and they become activated or they can bind to ligand that then binds to enzyme and binds to another enzyme to activate it
210
Ion channel coupled receptors use what type of channel
Transmitter gated ion channel and act between synapses
211
How do transmitter gated ion channels work
Turn chemical signal into electrical signal and changes membrane potential causing receptor to change conformation
212
What is the largest family of receptors
G protein coupled receptors
213
What is the structure of G protein coupled receptor
Weaves through membrane 7 times (transmembrane receptor protein)
214
Example of G protein coupled receptor
Photo receptor, olfactory receptor, yeast mating receptor
215
How is a G protein coupled receptor stimulated
Binds to a ligand, G protein becomes activated intracellularly
216
Structure of G protein
Contains three subunits (alpha, beta and gamma)
217
Inactivate form of G protein contains
GDP
218
Active form of G protein contains
GTP
219
When GTP removed on G protein what else separates
A subunit
220
How is a G protein stimulated
Activation of receptor, alpha-GTP and gammabeta subunit bind together and interact with intracellular targets to trigger cascade
221
How to inactivate G protein
Remove phosphate to become GDP
222
G protein inactivation example
Cholera toxin changes the alpha subunit preventing the conversion of GTP to GDP, G protein always active
223
What inactive protein causes G protein to always be off
Whooping cough, keep alpha subunit in inactive state
224
What activates ion channel
Subunits of G proteins activate ion channels or enzymes
225
Example of activation of ion channel
Acetylcholine binds to G protein receptor causes alpha subunit to activate that then causes gammabeta subunit bind to K+ channel to open it, to close it lose phosphate
226
How are enzymes activated in G protein coupled receptors
Target adenylyl cyclase which then produces cAMP that then could activate phospholipase C to produce IP3 and DAG
227
What activates second messengers
Stimulation of G proteins
228
How is cyclic AMP stimulated
Ligand binds to receptor to activate G protein and the alpha subunit turns of adenylyl cyclase and then activates and increase in cyclic AMP
229
How to inactivate cyclic AMP
Phosphodiesterase turns cAMP to AMP making it difficult to move through cell
230
Pathway of cAMP
CAMP binds to cAMP-dependent protein kinase to activate it so that it can phosphorylate intracellular proteins such as PKA
231
What causes PKA to change conformation
CAMP
232
What us calmodulin
Calcium binding protein that response to increase Ca2+, it will change conformation and wrap itself around target protein
233
What are the target proteins of calmodulin
CaM kinases
234
Where is the domain in the enzyme coupled receptors
Intracellular domain that is the enzyme
235
Enzyme coupled receptors are involved in changes in the
Cytoskeleton
236
Structure of RTKs (receptor tyrosine kinases)
Single pass protein with an alpha helix
237
How to RTKs become activate
Two RTKs come together to form a dimer active at the intracellular tails and the tails phosphorylate each other and act like a kinase
238
What are the stopping signal of RTKs
Protein tyrosine phosphotases that remove receptor
239
Where do you see Ras pathway in real life
Cancer which is overreaction of Ras and causes cell division
240
RTKS activating Ras causes phosphorylation cascade resulting in
Change in gene expression
241
Activated Ras protein can cause
Activation of MAP kinase cascade
242
What inhibits Ras
Antibodies in pathway grab Ras, cell cant respond to extracellular signals
243
What happens with overstimulation of Ras
Continuous cell proliferation, 30% of all cancer has Ras defect
244
PI 3-kinase promotes
Cell growth and survival
245
PI 3-Kinase phosphorylate s
Inositol phospholipids
246
AKT inactivate
Bad to promote cell survival
247
Akt activates what
Tor to promote cell growth
248
Cytokines activate
Gene regulatory proteins
249
Cytokine receptors associate with
JAKs
250
JAKs phosphorylate what gene regulatory proteins
STATs
251
Cellular receptors induce
Gene expression and cellular response
