Test 3 Flashcards
(194 cards)
1
Q
The outer envelope of chloroplast contains several kinds of ______, mitochondria have one.
A
porins
2
Q
The inner envelope membrane of chloroplast is _______ ________, meaning it (does/does not) allow fluid to pass through.
A
highly impermeable, does not
3
Q
The thylakoid membrane of chloroplast is flattened into sacs and the space inside is called the _____.
A
Lumen
4
Q
The __________ _________ of chloroplast contains the photosystems, ETC, and ATP synthase.
A
thylakoid membrane
5
Q
__________ contain a single outer membrane and the inner membrane has cristae joined to it at the organelle boundary.
A
Mitochondria
6
Q
The ________ of chloroplast contains the Calvin cycle, circular ds DNA, and ribosome.
A
stroma
7
Q
The ________ of chloroplast contains a high concentration of protons.
A
lumen
8
Q
Photosynthesis is the reverse of _______.
A
Respiration
9
Q
Respiration is the reverse of ______.
A
photosynthesis
10
Q
________ reduces O2 to water while _________ oxidizes water to O2.
A
Respiration, photosynthesis
11
Q
____________ reactions occur on membranes where light energy is absorbed and stored in ATP and NADPH.
A
Light-dependent
12
Q
___________ reactions use energy from ATP and NADPH to synthesize carbohydrates.
A
Light-independent
13
Q
Light-independent reactions are also known as the _____ ______. However, this is wrong because it can happen in the light also. It is also call _____ _____. This is more accurate.
A
dark reactions, carbon fixing
14
Q
____________ are the primary photosynthetic pigments.
A
Chlorophylls
15
Q
What is the structure of chlorophylls?
A
porphyrin ring + phytol ring
16
Q
Chlorophylls absorb ___ and ____ light while reflecting _____ and _____ light.
A
blue/red, green/yellowish
17
Q
_____ are secondary light collectors. They draw excess energy from _____ preventing production of singlet oxygen.
A
Carotenoids, chlorophyll
18
Q
What is the structure of carotenoids?
A
a linear system of double bonds (C=C)
19
Q
Carotenoids absorb _____ and _____ light. They reflect ____, ______, and _____ light.
A
blue/green, red/orange,yellow
20
Q
Chlorophylls and carotenoids are found in _____.
A
chloroplasts
21
Q
Photons with shorter wavelengths have _____ energy.
A
greater
22
Q
Photons with _____ wavelengths have lower energy.
A
longer
23
Q
The number of orbitals an electron can exist in is limited, so ______________________________.
A
only certain wavelengths of light can be absorbed
24
Q
Energy in photosynthetic units can only pass to pigments that accept ____ or _____ _____.
A
equal or longer wavelengths/lower energy photons
25
_____________ ________ _______ pass energy through the photosynthetic units to the reaction center.
Light-harvesting antenna pigments
26
Where are the photosystems found in chloroplasts?
thylakoids
27
Which of the following would you not expect to find in the stroma?
A high concentration of protons.
28
Which statement contrasting photosynthesis and respiration is incorrect?
Photosynthesis uses an ETC, while respiration does not.
29
Non oxygenic photosynthesis uses _________ as the reducing agent and ________ as the oxidizing agent.
H2S: CO2.
30
The light-independent reactions of photosynthesis occur _________ and produce ________.
in the stroma, carbohydrates.
31
What color of light do caratenoids absorb?
green and blue.
32
As light energy passes through a photosystem, it is transferred:
to pigments that accept equal or longer wavelengths.
33
Photosystem I gets its electrons from:
PSII.
34
The oxygen evolving complex is composed of:
4Mn++, Ca++ and peripheral proteins
35
The correct order of electron flow during non cyclic photosynthesis is
PSII, plastoquinone, Cytochrome b6f, plastocyanin, PSI, ferredoxin,ferredoxin NADP+
reductase.
36
The herbicide Paraquat competes for electrons with:
Ferredoxin of the chloroplast
37
What do Cytochrome b6f of the chloroplast and Cytochrome bc1 of the mitochondria have in common?
Both engage in a Q cycle that translocates four protons for each pair of electrons.
38
Compared to the mitochondria the gradient in the chloroplast which is used to make ATP is:
largely a pH gradient.
39
First step in the Calvin cycle involves:
fixing carbon from CO2 to RuBP.
40
Which statement about Rubisco is true?
It is the most abundant enzyme on the planet.
41
Which of the following is found in both C4 and C3 plants?
1. Rubisco.
2. the Calvin cycle.
3. a four carbon photosynthetic pathway.
4. RuBP.
5. PEP carboxlyase.
1,2,4
42
Which statement about the glycocalyx is true?
It is made of oligosaccharides attached to the integral membrane proteins and lipids.
43
What could be defined as an organized network of extracellular materials found beyond the immediate vicinity of the plasma membrane?
extracellular matrix.
44
Which statement about collagen is true?
Cross linking of collagen fibers causes brittleness of bones.
45
The enzyme that binds collagen subunits together requires:
Vitamin C as the coenzyme.
46
Ehler-Danlos syndrome results from:
mutations in a number of collagen genes.
47
Which protein of the extracellular matrix is responsible for holding water to act as packing material that resists crushing?
Proteoglycan
48
Integrins bind to:
ligands in the extracellular matrix.
49
The drugs Aggrastat and Integrilin prevent blood clots by:
resembling the RDG motifs and binding to integrins on platelets.
50
Dynamic attachments between a cell and the extracellular matrix that occur during cellular movement are called a(n) ________.
focal adhesions
51
Which cell to cell binding protein binds to oligosaccharides?
selectins
52
Which cell to cell binding proteins are calcium dependent?
cadherins and selectins
53
What junctions are intermediate filaments involved in?
desmosomes, hemidesmosomes
54
Patients with leukocyte adhesion deficiency have repeated life-threatening bacterial infections due to the lack of:
integrins on the membranes of their neutrophils.
55
Cancers that have gained the ability to secrete metallo proteinases have gained the ability to:
penetrate barriers and move into other tissues.
56
The freeze fracture technique involves:
breaking cells along membranes and viewing them with a scanning electron microscope
57
Which statement about gap junctions is true?
They are important for cell-cell communication.
58
Plasmodesmata are:
plasma membrane lined channels that connect the cytoplasm of plant cells.
59
Which plant cell wall component is composed of a glucose backbone with xylose side chains, and is responsible for cross linking cellulose microfibrils?
hemicellulose
60
What molecules do secondary cell walls have more of than primary cell walls?
cellulose and lignin
61
All but which of the following is part of the endomembrane system?
mitochondria
62
Which pathway is responsible for moving proteins and complex carbohydrates out of cells in membrane bond vesicles?
the biosynthetic pathway
63
Movement of membrane bound vesicles from the plasma membrane to form endosomes is called:
retrograde direction
64
The sorting signals that target proteins to particular cellular compartments are made of _____________, and they are recognized by _________.
oligosaccharides and acetyl groups: organelle receptors
65
A tissue has been briefly labeled with radio-labeled amino acids. It is then transferred to a medium containing unlabeled amino acids. This can be done several times with different tissue samples for varying periods of time. What is the entire procedure called?
radio nitrogen trafficking
66
What would you use to locate organelle membrane proteins within a cell?
electron microscopes and antibodies
67
What is the effect on a yeast cell of a mutant gene involved in vesicle fusion?
Cells amass an excess number of unfused vesicles.
68
Green fluorescent proteins have made it possible to:
observe the movement of integral membrane proteins through living cells.
69
Whichof the following is a characteristic of rough endoplasmic reticulum?
it is continuous with the nuclear envelope
70
What is noteworthy about the detoxification enzymes in the smooth endoplasmic?
They lack substrate specificity
71
What are the differences between ribosomes that make secretory proteins and those that make proteins intended for the cytosol?
There are no differences between them.
72
Which statement about synthesis of secretory proteins is true?
A signal sequence of hydrophobic amino acids is produced at the beginning of the secretory protein.
73
How are integral membrane proteins thought to enter the lipid bilayer?
Hydrophobic sequences enter as they are formed when the translocon opens.
74
Membranes of the endomembrane system arise:
from preexisting ER membranes by insertion of new proteins and lipids.
75
Which statement about the growth and maintenance of unique membrane composition is false?
Lipid composition included in vesicles remains the same regardless of the organelle being formed.
76
Reactions Centers: 1) Light energy absorbed by the antenna is passed to the ______ ______. 2) Electrons of the _____ _____ are boosted to _____ ____. 3) Electrons are passed to a primary electron acceptor. 4) The reaction center becomes _____ charged. 5) ____ gets electron from H2O, ____ gets electrons from PSII. 6) ____ increases the electrons energy to a midpoint, ____ raises the level above that of NADP+.
reaction center, reaction center, outer orbitals, positively, PSII, PSI, PSII, PSI
77
The oxygen-evolving complex of photolysis (4Mn++, Ca++, and peripheral proteins) accumulates ______ _____ and transfers them one at a time to ____ which can only hold one at a time.
4 electrons, P680
78
What is the energy level of photosystem II? photosystem I?
P680, P700
79
In photolysis, _________________ must be absorbed by PSII to split 2H2O and make one O2.
four photons of light
80
Atrazine binds to ____ blocking plastoquinone.
PSII
81
Paraquet competes with ______ for PSI electrons.
ferredoxin
82
_____ can kill human cells by generating oxygen radicals when it takes electrons from Complex I (NADH dehydrogenase) of the mitochondria.
Paraquet
83
_________ is related in structure to Cytochromes bc1 of the mitochondria. Both have quinols as substrates. Both share similar redox groups. Both engage in a Q cycle that translocates 4 H+ for each pair of electrons. Both are affected by some of the same poisons.
Cytochrome b6f
84
The chloroplast pH gradient is largely a pH gradient because _______________________.
proton movement is followed by anions
85
ATP synthase in the thylakoid membrane produces ATP by __________.
chemiosmosis
86
The Calvin cycle begins and ends with _______.
RuBP (Rubisco)
87
Products of the Calvin cycle include _____________ and __________.
G3P sucrose in the cytosol and G3P starch in the chloroplast.
88
Rubisco is one of the key enzymes of the ______.
biosphere
89
What is the most abundant protein on the earth?
Rubisco
90
Rubisco has one of the worst _________ of any known enzyme.
turnover rates
91
When O2 levels are high and CO2 levels are low, ________ slows down and _______ increases.
photosynthesis, photorespiration
92
During ___________, Rubisco binds O2 to RuBP. The product of this reaction is sent to a ________ and then a mitochondria where ___ is produced.
photorespiration, peroxisome, CO2
93
In C3 plants, _____ cells fix carbon in the Calvin Cycle using Rubisco.
mesophyll
94
____ are chains of sugars attached to integral membrane proteins and some lipids.
Glycocalyx
95
What are the 5 functions of glycocalyx?
| 1) project.... 2) mediate... 3) provide... 4) bind... 5) serve...
1) project from the plasma membrane 2) mediate cell-cell interactions 3) provide protection 4) bind regulatory factors 5) serve as barriers to particles
96
The _____________ is an organized network of covalently bound material beyond the plasma membrane that may control the shape of activities of cells due to different mixes of proteins.
Extra cellular matrix
97
A __________________ is a matrix that forms a sheet surrounding muscle, fat, underlines epithial tissue, digestive and respiratory tracts, and lines blood vessels.
basement membrane
98
Extra cellular matrix of cartilage tissue is made from _______ and ______, and gives cartilage _________ and ___________.
collagen and proteoglycan, strength and resistance to deformation
99
__________ are proteins of the EMC. They form fibers of great strength.
Collagens
100
__% of a human's protein may be collagens.
25
101
Collagens are made by what 3 things?
fibroblasts, muscle cells, and epithelial cells.
102
Collagen timers come together to form _______.
rod-shapes fibers
103
Fibrillar collagens form ___________ fibers.
large cable-like
104
_______ ___________ of fibrillar collagen continues throughout life strengthening the fibers, but leads to decreased elasticity of the skin and brittleness of bones in the elderly.
Cross linking
105
Scar tissue due to burns or trauma is caused by an accumulation of ________________.
fibrillar collagen
106
Collagen is laid like what to help strengthen them?
bricks
107
______ is due to a vitamin C deficiency. Vitamin C is a coenzyme for the enzyme that binds collagen together. Symptoms of this include what 4 things?
Scurvy; inflamed gums, poor wound healing, brittle bones, and weakening of the lignin of blood vessels causing internal bleeding.
108
Mutations in a number of collagen genes can lead to _______ _________.
Ehler-Danlos syndrome
109
Other proteins of the ECM include what 3 proteins?
Proteoglycans, fibronectin, and laminin
110
_______ bind cations that bind water to act like packing material that resist crushing.
Proteoglycans
111
_______ is two polypeptide chains that provide binding sites for ECM molecules and cells, and guides cells during embryonic development.
Fibronectin
112
______ is extra cellular glycoproteins made of three polypeptides linked by sulfide bonds which can influence migration, growth and development.
Laminin
113
The following are functions of what? (Bonus.. List these functions)
Packing material, glue, determine the shape and activities of cells, provide support for attached cells, acts as a barrier to macromolecules, stratum for cell migration, prevents invasion by cancer cells
Extra Cellular Matrix (ECM)
114
_____ link the cell surface with the ECM.
Integrins
115
Integrin's _____ _______ _________ _____ can have an affinity for ligands as they change from their inactive to their active forms. Their legs bind to the membrane. The cytoplasmic ends of the legs separate when talin attaches, causing the integrin to move upright out from the membrane surface, giving it its active form so it can bind a ligand.
extra cellular globular component
116
________ is an arginine-glycine-aspartic acid sequence of a ligand that binds the integrin.
RGD motif
117
______ ______ can cause a conformational change on the cytoplasmic end of the integrin which allows the integrin to interact with nearby proteins. This results in transmission of an outside-in signal.
Integrin-ligand binding
118
________ are changes in an integrin’s affinity after cytoplasmic activation. Platelets require this type of signal to attach to fibrinogen during blood clot formation. Aggrastat and Integrelin are antithrombotic drugs that resemble RGD structure.
Inside-out Signaling
119
_______ _________ can influence cell behaviors such as differentiation, motility, growth and survival. Cancer cells can grow in liquid suspension cultures. Normal cells require integrin binding to transmit life-saving information.
Outside-in signaling
120
List the functions of the extracellular matrix.
| Bonus!!!
Packing material, glue, determine the shape and activities of cells, provide support for attached cells, acts as a barrier to macromolecules, stratum for cell migration, prevents invasion by cancer cells
121
__________ are scattered, discrete sites where an integrin attaches to an outside surface and with adaptor molecules to actin of the cytoskeleton. These adhesions are dynamic and are involved in attachment and movement.
Focal Adhesions
122
________ is the tightest attachment between a cell and its ECM. They contain a dense layer of keratin filaments projecting out from the plasma membrane.
Hemidesmosome
123
_______ bind cells of similar type together to form a “cell-adhesion zipper.”
Cadherins
124
Cadherins bind to the _____________.
cadherins of other cells
125
Cadherins are _____ dependent. They have a _____ construction, and are thought to be responsible for the dynamic changes in _______ _______ that lead to morphogenesis.
calcium, modular, adhesive contacts
126
Selectins bind to __________.
oligosaccharides
127
______ mediate interactions between leukocytes and vessel walls at sites of inflammation.
Selectins
128
Like cadherins, selectins are _________ dependent and have a _____ construction.
calcium dependent, modular construction
129
__________ like proteins that bind to many different cell surface proteins.
Immunoglobulin (Ig)
130
_________ __________ mediate reactions between lymphocytes and macrophages.
Immunoglobulin Superfamily (IgSF)
131
Immunoglobulin Superfamily (IgSF) have a ____ construction and are calcium (dependent/independent).
modular, independent
132
Immunoglobulin Superfamily (IgSF) are found in _______ that do not have a _____________.
invertebrates, classic immune system
133
Immunoglobulin Superfamily (IgSF) originally evolved as what?
Cell surface receptors (which are the classic immune system. That don't have antibodies but have immune systems.)
134
_____ _____ and ______ are cell-cell connections that involve cadherins.
Adherens Junctions and Desmosomes
135
___________ are common in epithelia, like that in the intestine, where they encircle cells at apex with a belt.
Adherens Junctions
136
With ________________, cadherin proteins connect external environment with actin in cytoplasm.
Adherens Junctions
137
_________ can provide pathway for signals into the cell.
Adherens Junctions
138
________ are disc shaped adhesive junctions. They are numerous in cells subjected to stress like cardiac muscle. Cadherins attach to dense cytoplasmic plaque and intermediate filaments.
Desmosomes
139
_______ ______ allows the observation of the internal membrane faces by breaking the top of the membrane off. It is used with a scanning electron microscope (SEM)
Freeze Fracture
| This is on test.
140
_______ ________ are made of interconnected strands of paired protein that run parallel to the apical surface of the cell.
Tight Junctions
| This is on test.
141
_______ _______ form a gasket that serves as a barrier to movement of water and solutes from one side of an epithelial sheet to the other.
They can selectively allow movement of specific substrates.
They can maintain the polarized character of epithelial cells by acting as a fence blocking diffusion of integral proteins.
Tight Junctions
| This is on test.
142
Tight Junctions are very _______ and are composed of at least __ different proteins. The first extracellular loops of several claudins, which have been tested for charge selectivity.
complex, 40
143
__________ are pipelines made from six connexin proteins.
Gap Junctions
144
Gap junctions allow ______ of 1000 Daltons, are ____ _____ channels, open in high _____ _____
diffusion, non selective, calcium concentrations
145
Gap junctions make cytoplasm of cells _______. They are important for ______ tissue and for _____ _____.
continuous, non vascular, cell-cell communication (sending signals)
146
Tight junctions are ____ of proteins while gap junctions are _____ proteins.
pairs, sets of 6
147
Gap junctions are found in what type of cells? Plant or animal?
animal
148
______ are pipelines between plant cell walls.
Plasmodesmata
149
Plasmodesmata are lined with ______ formed from ER, makes _____ continuous, dilate to allow passage of 5000 Dalton molecules, _____ and ____ can pass, can lead into the _____ ____ (so they throughout the whole plant).
desmotubule, cytoplasm, proteins and RNAs, vascular system
150
_____ is fibrous material that forms microfibrils of 36 cellulose molecules oriented parallel to each other.
Cellulose
151
What are the 3 main components of a plant cell wall?
cellulose, matrix, and proteins
152
The matrix of a plant cell wall is made up of ________ and _______.
Hemicelluloses, Pectins
153
______ are the backbone of glucose with xylose side chains which cross link microfibrils together.
Hemicelluloses
154
_____ are negatively charged polysaccharide containing galacturonic acid, hydration forms gel around it.
Pectins
155
____ expansins of a plant cell walls relax cell walls so turgor pressure causes the cell to grow.
Proteins
156
What is the main component of cell walls? What is it made of?
cellulose, glucose
157
The _______ is a thin cell wall of young growing cells while the __________ is a thick cell wall of older cells that contains Additional cellulose and Lignin.
Primary Cell Wall, Secondary Cell Wall
158
The ____________ is a network of organelles that shuttle materials and membranes back and forth. Organelles that are part of the system include endoplasmic reticulum, Golgi complex, plasma membrane, transport vesicles, vacuoles, endosomes, and lysosome, nuclear membrane.
Endomembrane System
159
______, ______ and _____ are NOT part of the endomembrane system.
Mitochondria, chloroplasts, and peroxisomes
(We will either have to determine parts that are or parts that are not part of the endomembrane system. Memorize these 3 that are not and remember every other part is.)
160
The ________ moves proteins and complex carbohydrates out of the cell in membrane bound vesicles while the _____ moves material from outside the cell into membrane bound vesicles inside the cell.
Biosynthetic Pathway, Endocytic Pathway
161
Both the biosynthetic pathway and the endocytic pathway can be _________ or __________. Vesicles move by _____ _____, tracts of microtubules and microfilaments, and sorting signals.
regulated or constitutive, motor proteins
162
_______ ____ always move forward or in an _______ direction.
Transport vesicles, anterograde
163
________ can move backward or in a _______ direction. This can return membrane materials and some contents to the original cisterna.
Membranes, retrograde
164
What are the two ways to target proteins to a particular Compartment?
1) ________ on proteins made of amino acid sequences and oligosaccharides 2) ______ which recognize sorting signals
sorting signals, vesicle receptors
165
_________ ______ reveals the site of pancreas enzyme production. Labeled amino acids are followed by _______________. Then sections for TEM were covered with photographic emulsions.
Pulse/Chase Autoradiography, non-labeled amino acids
166
During a Pulse/Chase Autoradiography, 3-minutes after the pulse, radioactivity is located where?
40-minutes after the pulse, radioactivity is located in the ________ and __________.
in the RER, Golgi complex and secretory granules
167
Techniques for Determining Organelle Membrane Proteins:
| 4 ways
1. ) Subcellular fractionation by homogenizing, centrifugation, and gradient techniques
2. ) Biochemical analysis
3. ) Antibodies used to isolate proteins or locate them with TEM
4. ) Mass spectrometry
168
______ ______ ________ – mutants are selected which have abnormal vesicle distribution. Mutant genes have been cloned and sequenced.
Protein Trafficking Mutants
169
______ _______ indicates these Protein Trafficking Mutant systems are conserved in fungi, plants and animals.
_____ indicate each step in protein trafficking.
Sequence data, Mutants
170
If there is an accumulation of expanded RER (Rough ER), vesicles are _______________.
not forming
171
If a cell accumulates an excess number of unfused vesicles, there is a ______ in the ____ _____.
mutation, fusion gene.
172
Green Fluorescent Proteins (GFPs) are known as what?
Jelly fish protein (kind of like the lightning bug chemical)
173
A GFP gene is studied by ___________. The resulting chimeric protein can be observed in living cells _________.
fusing it to a gene, as it is transported
174
Which has ribosomes? The smooth ER or rough ER?
RER
175
The RER has _____ cisternae while the SER has ____ cisternae.
flattened, tubular
176
The ___ ER is continuous with the outer nuclear membrane.
Rough
177
The ___ ER's cisternae form an interconnecting system.
smooth
178
The ____ ER produces rough-surfaced vesicles while the ___ ER produces smooth-surfaced vesicles.
Rough, smooth
179
The RER's function is to produce _____, _____, and _____ that journey through cell membranes.
proteins, phospholipids, and carbohydrates
180
Membranes arise from ___________________ by inserting newly synthesized proteins and lipids.
growth of preexisting ER membranes
181
New membranes do not arise from ______.
scratch
182
As membranes move from one compartment to another, its ____ and ____ are modified by the various organelles.
proteins and lipids
183
Lipid composition included in vesicles differs depending on the _____________.
organelle being formed
184
Each organelle has _______ that make their proteins and lipids unique.
enzymes
185
__________________ can bind and transfer phospholipids from one membrane to another.
Phospholipid-transfer proteins
186
Where is membrane asymmetry established?
In the ER
187
_______ _______ is maintained as vesicles bud and fuse from one compartment to the next.
Membrane asymmetry
188
______ move lipids from one leaflet to the other.
Flippases
189
The _____ of the ER and Golgi is a lot like the extracellular space.
lumen
190
____________ removes the final glucose from the glycoprotein before it moves to the next compartment, releasing the protein from the ER chaperone.
Glucosidase ll
191
Misfolded proteins are recognized by a monitoring enzyme (GT) which adds a _______ and the protein binds the __ _____ allowing a second chance at proper folding.
glucose, ER chaperone
192
Misfolded proteins are sent to the _____ where the _______ ____ are removed and proteasomes destroy the protein (ER associated degradation ERAD).
cytosol, oligosaccharide chains
193
_______ ______ _____ is triggered when too many misfolded proteins have accumulated.
Unfolded Protein Response (UPR)
194
An Unfolded Protein Response (UPR) stimulates: ER-chaperones that can ___________, Proteins that transport the misfolded out of the RE, Proteins that ______ misfolds, Protein synthesis is inhibited giving the ER an opportunity to ________, and If all else fails, the _________ ______ is triggered.
help the protein return to their native state, destroy, remove the misfolds, cell-death pathway
