Chapter 15 Flashcards
1
Q
Name the organelle: Metabolic pathways, protein synthesis
A
cytosol
2
Q
Name the organelle: contains nuclear genome, DNA and RNA synthesis
A
nucleus
3
Q
Name the organelle: ATP Synthesis by oxidative phosphorylation, own DNA and ribosome
A
mitochondria
4
Q
Name the organelle: ATP Synthesis and carbon fixation by photosynthesis, own DNA and ribosome
A
chloroplasts
5
Q
Name the organelle: membrane synthesis, protein distribution
A
ER
6
Q
The ER that has ribosomes attached is
A
rough
7
Q
The ER that has the steroid hormone synthesis, Ca2+ sequestration
A
Think of Milk when you see calcium. And milk is rich and smooth.
Smooth ER
8
Q
Name the organelle: proteins and lipid modification and sorting
A
Golgi apparatus
9
Q
Name the organelle: intracellular degradation
A
lysosomes
10
Q
Name the organelle: sorting of endocytosed material
A
endosomes
11
Q
Name the organelle: oxidation of toxic molecules
A
peroxisomes
12
Q
Which organelles form part of the endomembrane system?
A
ER, Golgi apparatus, lysosomes, endosomes, peroxisomes
13
Q
The _____ system is a set of organelles that extensively communicate via vesicle budding
A
endomembrane
14
Q
Mitochondria or chloroplast form part of the endomembrane system because they are thought to have come from the engulfment of an ancient prokaryotic cell. True or false?
A
False. Both do not form part of the endomembrane system.
15
Q
Name the organelle: ATP synthesis of oxidative phosphorylation.
A
mitochondria
16
Q
Name the organelle: Intracellular degradation
A
lysosomes
17
Q
Name the organelle: ATP synthesis and carbon fixation by photosynthesis
A
chloroplasts
18
Q
Name the organelle: oxidative breakdown of toxic molecules
A
peroxisomes
19
Q
Name the organelle: modification, sorting, packaging of proteins and lipids for either secretion or delivery to another organelles
A
Golgi apparatus
20
Q
Name the organelle: synthesis of most lipids; synthesis of proteins for distribution to many organelles and to the plasma membrane
A
ER
21
Q
Name the organelle: contains the main genome; DNA and RNA Synthesis
A
nucleus
22
Q
Name the organelle: contains many metabolic pathways, protein synthesis; the cystoskeleton
A
cytosol
23
Q
The volume of the cytosol in typical eukaryotic cell is about ___.
A
50%
24
Q
____, ____, and ____ are each surrounded by a double membrane.
A
Nucleus, mitochondria and chloroplast
25
Organelles like the Golgi apparatus, lysosomes, and the ER have a ____ membrane.
single
26
The synthesis of virtually all proteins in the cell begins on ribosomes in the \_\_\_\_\_\_. The exceptions are the few ____ and _____ proteins that are synthesized on ribosomes inside these organelles.
cytosol; mitochondria; chloroplasts
27
What are the three mechanisms of protein transport into organelles?
1- Transport through nuclear pore; 2- Transport across membrane; 3- Transport by vesicles.
28
\_\_\_\_ proteins enter through nuclear pores.
folded
29
\_\_\_ proteins enter organelles via protein translocators.
unfolded
30
Unfolded proteins enter organelles via protein \_\_\_\_.
translocators.
31
\_\_\_\_ proteins move via transport vesicles that fuse with destination membranes.
Folded
32
\_\_\_\_ direct proteins to the correct organelle.
signal sequences
33
Signal sequences have a continuous stretch of ___ amino acids.
3-60
34
What happens if the cystolic protein has no signal sequence?
It stays in the cytosol
35
What is the signal sequence for the retention in lumen of ER?
Think... Before I go to the ER, I need:
Listerine, Aspirin, Glue... Then LEave and stay COOl.
Lys-Asp-Glu-Leu-COO-
36
What is the signal sequence for Import into nucleus?
Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val
37
Which amino acids are positively charged for the following signal sequences: Lys-Asp-Glu-Leu-COO-
Lys
38
Which amino acids are negatively charged for the following signal sequences: Lys-Asp-Glu-Leu-COO-
Think... In the ER, taking aspirin and glue will result in negative consequences.
Asp-Glu
39
Which amino acids are positively charged for the following signal sequences: Pro-Pro-Lys-Lys-Lys-Arg-Lys-Val
Think.... Lysterine and Argentina have a positive meaning for me.
Lys-Lys-Lys-Arg-Lys
40
Which amino acids are negatively charged for the following signal sequences: Pro-Pro-Lys-Lys-Lys-Arg-Lys-Va
none
41
What would happen if you add a signal sequence (for the ER) to the N-terminal end of a normally cystolic protein? (Assume in each case that the protein involved is a \*\*soluble\*\* protein, not a membrane protein.)
The protein will now be transported into the ER lumen.
42
What would happen if you change the hydrophobic amino acids in an ER signal sequence into charged amino acids? (Assume in each case that the protein involved is a \*\*soluble\*\* protein, not a membrane protein.)
The altered signal sequence will not be recognized and the protein will remain in the cytosol.
43
What would happen if you change the hydrophobic amino acids in an ER signal sequence into other hydrophobic amino acids? (Assume in each case that the protein involved is a \*\*soluble\*\* protein, not a membrane protein.)(
The protein will still be delivered into the ER.
44
The __ nuclear membrane is continuous with the __ membrane.
outer; ER
45
In the nucleus, the mesh-work of protein filaments provides ____ support. What type of protein filaments are these called?
structural; nuclear lamina
46
In the structure of the nucleus.... the _____ form the gates through which molecules enter or leave the nucleus.
nuclear pores
47
The inner and outer nuclear membranes form the _____ of the nucleus.
nuclear envelope
48
What is the term the describes a large, elaborate structure composed of a complex of about 30 amino acids.
nuclear pore
49
What prevents the passage of large molecules but allowing small, water-soluble molecules to pass freely and non-selectively between the nucleus and the cytosol?
nuclear pore complex
50
Folded proteins with nuclear localization signals are bound by \_\_\_\_.
nuclear import receptors
51
Nuclear import receptors and cargo cross the nuclear envelope via the \_\_\_\_.
nuclear pore
52
\_\_\_ binds to the nuclear import receptor in the nucleus and returns it to the cytoplasm.
Ran-GTP
53
\_\_\_\_\_ hydrolysis drives nuclear transport.
GTP
54
Dr. Kim has discovered a drug that blocks the ability of Ran to exchange GDP to GTP. What is the most likely effect of this drug on nuclear transport?
Nuclear transport receptors would be unable to release their cargo in the nucleus.
55
Unfolded proteins enter mitochondria (chloroplasts) via \_\_\_\_\_.
protein translocators
56
In the mitochondria, the unfolded proteins diffuse laterally in the ___ membrane until it encounters a second ____ in the inner membrane.
outer; translocator
57
A mitochondrion has an ___ and ____ membrane, and each membrane has its own protein \_\_\_\_.
outer; inner; translocator
58
What is the most extensive membrane network in eukaryotic cells?
ER
59
When translating proteins with ER signal sequences, _____ are targeted to the ER.
ribosomes
60
All ribosomal subunits return to the common pool in the \_\_\_\_\_.
cytosol
61
ER protein targeting depends on the interaction between the ______ and the \_\_\_\_\_.
signal recognition particle; SRP receptor
62
ER proteins are threaded through a \_\_\_\_\_\_\_\_\_.
protein translocator
63
SRP and SRP receptor bind and hydrolize \_\_\_.
GTP
64
In the ER, the SRP is displaced and released for \_\_\_.
reuse
65
After signal sequence cleavage, soluble proteins are released into the \_\_\_.
ER lumen
66
After signal sequence cleavage, soluble proteins are released into the ER lumen. The signal peptide is now _____ and then the cleaved signal is going to be ___ later.
cleaved; ejected
67
Using genetic engineering techniques, you have created a set of proteins that contain two (and only two) conflicting signal sequences that specifiy different compartments. Predict which signal would win out for the following combinations.
The protein would enter the ER. ER sorting signal would supersede a nuclear localization signal.
68
The arrangement of ER membrane proteins is determined by hydrophobic _______ and ______ sequences.
start transfer; stop transfer
69
What is 1?
hydrophobic start-transfer sequence
70
What is 2?
cytosol
71
What is 3?
ER Lumen
72
What is 4?
COOH
73
Which is the mature single-pass transmembrane protein in ER membrane?
5
74
Which # represents the hydrophobic stop-transfer sequence?
6
75
Transport vesicles carry soluble proteins and membrane between \_\_\_\_\_.
compartments
76
During \_\_\_\_\_, this vesicle here fuse with a plasma membrane and release its content, the outside
exocytosis
77
In \_\_\_\_\_\_, extracellular material is captured by vesicle and then inward from the plasma membrane and is carried into the cell.
endocytosis
78
Transport by ___ moves proteins and lipids between membrane compartments.
vesicles
79
What type of pathway is the ER to the GA to the plasma membrane, and ER to the GA to endosome to the lysosome.
Secretory
80
What type of pathway is the plasma membrane to the lysosome?
endocytic
81
To function optimally, each transport vesicle that buds off from a compartment must take with it only the proteins ________ to its destination and must fuse ____ with the appropriate target membrane.
appropriate; only
82
\_\_\_\_\_ is driven by the assembly of a protein coat.
Vesicle budding
83
\_\_\_ vesicles bud from membrane surfaces.
coated
84
What is the origin and destination of the following coat proteins: clathrin + adaptin 1
Golgi apparatus; lysosomes (via endosomes)
85
What is the origin and destination of the following coat protein: clathrin + adaptin 2
plasma membrane; endosomes
86
What is the origin and destination of the following coat protein: COP proteins
ER, Golgi cisterna, Golgi apparatus;
Golgi apparatus, Golgi cisterna, ER
87
Vesicles that bud from membranes usually have a distinctive protein coat on their cytosolic surface and are therefore called coated vesicles. What are the functions of the coat?
1- It helps shape the membrane into a bud;
2- It captures molecules for onward transport
88
\_\_\_\_\_ receptors recognize transport signals on cargo molecules and bind.
cargo
89
\_\_\_\_ mediate the connection between coat proteins and cargo receptors
Adaptins
90
\_\_\_\_\_ (binds GTP) pinches off the vesicle.
dynamin
91
\_\_\_\_ and ____ are involved in the initial shaping of the vesicle into the pit.
clathrin; adaptin
92
How does a transport vesicle select its particular cargo?
Second class of coat proteins called adaptins does the job.
93
What are the 2 functions of the adaptins?
1- Secure the clathrin coat to the vesicle membrane;
2- Help select the cargo molecules for transport
94
Dr. Kim has just joined a lab that studies vesicle budding from the Golgi and has been given a cell line that does not form mature vesicles. She wants to start designing some experiments but wasn't listening carefully when she was told about the molecular defect of this cell line. She's too embarrassed to ask and come to you for help. She does recall that \*\*\*this cell line forms coated pits but vesicle budding and the removal of coat proteins don't happen\*\*\*. Which of the following proteins might be lacking in this cell line?
dynamin
95
After a transport vesicle buds from a membrane, coated vesicle rapidly lose its protein coat and then it must find its way to its correct destination to deliver its content. How?
Docking and fusion and mediated by proteins on the surface of the vesicle and target membrane, including Rab and SNARE proteins.
96
\_\_\_ proteins on the surface of each type of vesicles are recognized by corresponding tethering proteins on the cytosolic surface of the target membrane.
Rab
97
Once the tethering protein has captured a vesicle by grabbing hold of its Rab protein, _____ on the vesicle interact with complementary _____ on the target (t-SNARE) membrane.
SNAREs; SNAREs
98
The same SNAREs play a central role in catalyzing the membrane \_\_\_.
fusion
99
\_\_\_\_ the soluble contents.
100
What are the protein-protein interactions that mediate fusion of transport vesicles?
Tethering
Docking
Fusion
101
\_\_\_ proteins are involved in the recognition of the transport vesicle with its target membrane.
Rab
102
\_\_\_ are transferred to asparagines by oligosaccharide protein transferase.
Pre-formed oligosaccharides
103
The unfolded ER protein pass through the translocator right so now you need to modify in the \_\_\_.
ER lumen
104
Proteins are modified by ___ in the \_\_\_.
enzymes; ER
105
What is the purpose of disulfide bond formation?
Helps stabilize the protein structure
106
Addition of oligosaccharide side chains is termed \_\_\_\_.
glycosylation
107
What is the purpose of glycosylation?
1- Protein protection from degradation
2- Keeps the protein in the ER until it is properly folded;
3- Acts as a transport signal for packaging the protein into appropriate transport vesicle;
4- Cell-cell recognition
108
Name the two types of protein modification that can occur in the ER but not in the cytosol.
1- Disulfide bond are formed by the oxidation of pairs of cysteine side chains (This does not occur in the cytosol because of its reducing environment.)
2- Proteins in the ER can undergo glycosylation. (Glycoysylating enzymes are not found in the cytosol. An oligosaccharyl transferase is a membrane-bound enzyme that has its active site exposed on the lumenal side of the ER membrane.)
109
Exit from the ER is \_\_\_.
selective
110
What are the reasons proteins remain in the ER?
1- Have an ER retention signal (4 aa);
2- Are incorrectly folded (retained by chaperones);
3- Are incorrectly assembled multimeric proteins (retained by chaperones)
111
\_\_\_\_ prevent misfolded or partially assembled proteins from leaving the ER.
chaperones
112
Accumulation of misfolded proteins in the ER lumen triggers an \_\_\_\_\_\_.
unfolded protein response (UPR)
113
Proteins are further modified and sorted in the \_\_\_\_.
Golgi apparatus
114
\_\_\_ golgi network faces the ER, It buds vesicles that return to the ER or continue through the Golgi apparatus.
cis
115
\_\_\_ golgi network faces the plasma membrane. It buds vesicle destined for the plasma membrane or other compartments.
trans
116
The fusion of a vesicle (transport or secretory) with the plasma membrane is \_\_\_.
exocytosis
117
Secretory proteins are released from the cell by \_\_\_\_\_.
exocytosis
118
What are the two distinct types of exocytosis that proteins (and lipids) move to the plasma membrane?
unregulated exocytosis;
regulated exocytosis
119
Which exocytosis default by pathway and transport vesicles are continuously fusing?
unregulated
120
Which exocytosis occurs only in some cells and the secretory vesicles do not fuse until a signal is received?
regulated
121
\_\_\_ vesicles do not fuse until a signal is received.
secretory
122
Both the unregulated and regulated exocytosis diverge in the \_\_\_\_. Also, specify if it cis or trans.
trans Golgi network
123
Secretory vesicles ______ and _____ concentrated proteins.
store; release
124
What are the 3 types of sorting compartments for the endosomes?
Recycling; Degradation; Transcytosis
125
In endosomes, ____ is the terms that occurs when receptors return to the plasma membrane.
recycling
126
In endosomes, ____ is when the receptors/cargo and contents of the lumen move to \_\_\_\_\_.
degradation; lysosomes
127
In endosomes, _____ occurs when receptors (& cargo?) move to a new plasma membrane area.
transcytosis
128
\_\_\_\_\_ digest extracellular materials and old organelles.
lysosomes
129
\_\_\_\_ is the uptake of material into cell by membrane invagination and internalization of the resulting vesicle.
endocytosis
130
\_\_\_\_\_\_ is the uptake of particles into large vesicles called \_\_\_\_\_.
phagocytosis; phagosomes
131
Phagocytosis occurs in ____ cells. Phagosomes fuse with \_\_\_\_.
phagocytic; lysosomes
132
\_\_\_\_\_involves the intake of molecules and fluid and is active in all cells.
Pinocytosis
133
Pinocytosis are indiscriminate, occurs via _____ coated pits and vesicles, and vesicles fuse with \_\_\_\_\_.
clathrin; endosomes
134
\_\_\_\_\_\_\_\_\_ is the selective endocytosis of specific macromolecules.
Receptor-mediated endocytosis
135
Receptor-mediated endocytosis occurs in \_\_\_\_\_\_.
low density lipoproteins
136
Pathway to lysosomes.... _____ is the enclosure of an old organelle in a double membrane creating autophagosome.
autophagy
137
Lysosomal enzymes are all ___ hydrolases, which have optimal activity at a low pH of about \_\_.
Acidic; 5
138
Fully folded proteins can be transported into which of the following organelles?
nucleus
139
Which of the following organelles is the site of steroid hormone synthesis in endocrine cells?
Smooth ER
140
Nuclear pores restrict larger molecules from traversing the membrane due to their
interwoven meshwork of protein fibrils.
141
Which of the following accurately describes a step in GTP-driven nuclear transport?
Binding of Ran-GTP to the receptor releases the cargo protein.
142
In which process do Rab proteins function?
vesicle tethering
143
What is one of the main differences in the behavior of the proteins in a vesicle destined for constitutive secretion, and the proteins in the vesicle destined for regulated secretion?
Proteins in the regulated secretion vesicle tend to aggregate and become highly concentrated in the ionic conditions in the vesicle.
144
Which of the endocytic pathways involves the ingestion of large particles or microorganisms and is performed mainly by specialized cells?
phagocytosis
