Test 3 Review Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q
After isolating the rough ER, you purify. 
What would you expect from the rough ER?
A: soluble secreted protiens 
B:ER membrane proteins 
C:Neither 
D: Both A and B
A

A: soluble secreted protiens
B:ER membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of the following states about vesicle budding from Golgi Apparatus is false?
A: Clathrin molecules are important for binding to and selecting cargoes for transport
B:Adaptins interact with clathrin
C:Once vesicle budding occurs and the vesicle comes into close proximity with the target membrane, clathrin molecules are released from the vesicle
D: Clathrin molecules act at the cytosolic surface of the Golgi membrane

A

A: Clathrin molecules are important for binding to and selecting cargoes for transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following statements is true?
A: The signal sequence on mitochondrial proteins are nomally C-terminal
B: Most mitochondrial proteins are not imported from the cytosol but are synthesized inside the mitochondria
C: Chapterone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes
D: Mitochondrial proteins cross the membrane in their native, folded state

A

C: Chapterone proteins in the mitochondria facilitate the movement of proteins across the outer and inner mitochondrial membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Glucogenesis refers to?

A

The synthesis of glucose from small molecules like pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Useful energy is obtained by cells when?

A

sugars are broken down by glycolysis, citric acid cycle, and oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the name of the specialized junction between neuron and target cells?

A

synapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F

Each of the three respiratory enzyme complexes includes metal atoms tat are tightly bound to protiens

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The localization information for protein signaling in a eukaryotic cell is contained in _______ of the proteins.

A

amino acid sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Proteins enter the nucleus in their ______ forms.

A

folded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Proteins that remain in the cytosol don’t contain a ________.

A

signal sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The proteins transported in to the ER by _______ in their _____ forms.

A

protein translocators

unfolded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What drives the production of ATP from ADP and Pi by ATP synthase?

A

A proton gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The drug dinitrophenol (DNP) makes the inner mitochondrial membrane permeable to hydrogen ions. When added to mitochondria DNP does?

A

decreases production of ATP and affect the PH gradient across the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which component of the electron transport chain is required to combine the electrons with molecular oxygen?

A

Cytochrome C oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a characteristic or measurment used to study the action potentials?

A

effects of a depolarizing stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following statements about the endoplasmic reticulum is true?
A: The ER is the major site of new membrane synthesis in the cell
B: Proteins are to be delivered to the ER are synthesized on the ribosome of the rough ER
C: Neither
D: Both A and B

A

Both A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the order through which a protein destined for the plasma membrane travels?

A

Er> Golgi>Plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of the following statements about the unfolded protein response (UPR) is false?
A: Misfolded proteins bind to receptors that stimulare the production of a transcription regulator
B: Activation of UPR results in chaperon production of more chaperon proteins
C:Actications of the UPR results in the transcript. Regulator translocation to nucleus
D: None of the above

A

None of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

T/F

In secretory cells the regulated and constitutive pathways of exocytosis diverge the trans golgi network. A constitutive secretory pathways is one that operates only when extracellular signal stimulates their secretion

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the role of the nuclear localization sequence in a nuclear protein?

A: it is bound by cytoplasmic nuclear receptor proteins that direct the nuclear protein to the nuclear pore

B: It is a hydrophobic sequence that enables the protein to enter the nuclear membranes

C: It aids in protein unfolding so that the protein can threat through nuclear pores

D: It prevents the protein from difffusing out of the nucleus through nuclear pores

A

it is bound by cytoplasmic nuclear receptor proteins that direct the nuclear protein to the nuclear pore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

N-linked oligosaccharides on secreted gylcoproteins are attached to

A: The cytosolic face of the ER
B: The serine or threonine residue in the growing polypeptide chain
C: The NH2 of an asparagine residue in the growing polypeptide chain
D: None of the above

A

The NH2 of an asparagine residue in the growing polypeptide chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

ATP molecules produced in the cytosol and glucose being converted to pyruvate are both what parts of oxidative phosphorylation?

A

Neither are part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

During an action potential which of the following actions does not help return membrane to its resting potential?

A

opening of voltage gated Na+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Most proteins destined to enter the ER are:

A: Transported across the membrane after synthesis is complete
B: Synthesized on ribosomes bound to ER membrane
C: Begin to cross membrane while still being synthesized
D: Both B and C

A

Both B and C

  • Synthesized on ribosomes bound to ER membrane
  • `Begin to cross membrane while still being synthesized
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

(During ATP synthesis) In chemiosmosis useful energy is harnessed by the cell from the movement of _____________ across the inner mitochondrial matric _______ its concentration gradient.

A

Protons; down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

T/F The enzyme that catalyzes the last irreversible reaction in glycolysis (STEP 10) yeilding a molecule each of ATP and pyruvate is called hexokinase.

A

False

-> The actual molecule is called pyruvate kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which of the following protein familes are involved in directing transport vesicles to the target membrane?

A: Snares
B: Rabs
C: Tethering proteins
D: All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which of the following statements concerning the ER signal sequence and/or the SRP is true?

A: THe SRP binds to the exposed ER signal sequence and to the ribosome, thereby slowing protein synthesis by the ribosome
B: The SRP-ribosome complex binds to an SRP receptor in the ER membrane
C: The SRP gets released, passing the ribosome to a translocation channel in the ER membrane
D: All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe events involved in propagation of an action potential?
A: An initial influx of Na+ though a small cluster of channels causes local depolarization of the membrane
B: Local depolarization causes nearby NA+ channels to open
C: Channels in depolarized regions of membrane are inactivated until the resting membrane potential is reestablished
D: All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Experimental Evidence supporting chemiosmotic hypothesis was gathered by using artificial vesicles containing a protein that can pump protons in one direction across the vesicle membrane to create a protein gradient. What protein is it?

A

Bacteriorhodopsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What mechanism does the inhibitory neurotransmitter prevent the postsynaptic cell from firing an action potential?

A

By opening Cl- channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The mitochondrial ATP synthase consists of several different protein subunits. Which subunit binds to ADP +P and catalyzes the synthesis of ATP as a result of conformational change?

A

F1 ATPase Head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Pyruvate is an important metabolic intermediate that can be converted into several other compounds, depending on which enzyme is catalyzing the reaction. Which of the following cannot be produced from pyruvate in a single enzyme-catalyzed reaction?

A: Lactate 
B: Oxaloacetate
C: Alanine 
D: All of the Above 
E: None of the Above
A

None of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the final ATP count during glycolysis?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Final ATP of pyruvate oxidation of acetyl CoA

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Final ATP of complete acetyl CoA oxidation?

A

15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Total ATP production?

A

30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the functions of lysosomes

A

degradation of worn out organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the function of the smooth ER?

A

steriod hormone synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the function of the golgi?

A

modify secreted proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is chemiosmotic coupling?

A

The linkage of electron transport, proton pumping and ATP sunthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What intracellular membrane bound structure contain both their own DNA and RNA?

A

mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

In an area of high ATP ultilization, what membrane bound organelle might you find there? AKA-> By a cardiac muscle cell

A

mitochondira

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the 4 seperate compartments of mitochondria?

A

Matrix, Inner membrane, Outer membrane, Intermembrane space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q
Hundred of Enzymes are located in this space, such as the enzymes required for oxidation of pyruvate and fatty acids for the citric acid cycle. What section of the mitochondria is this?
A:Matrix
B: Inner membrane
C: Outer membrane
D:Intermembrane space
A

Matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q
This space is folded into numerous cristae and contains proteins that carry out oxidative phosphorylation, including ATP synthase and the electron transport chain. What section of the mitochondria is this?
A:Matrix
B: Inner membrane
C: Outer membrane
D:Intermembrane space
A

Inner membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q
Containing large channel-forming proteins called porins, what section of the mitochondria is this?
A:Matrix
B: Inner membrane
C: Outer membrane
D:Intermembrane space
A

Outer membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

This space contains several enzymes that use the ATP passing out of the matric to phosphorylate other nucleotides. What section of the mitochondria is this?

A

Intermembrane space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

NADH donates it’s high energy electrons to?

A

the electron transport chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

The chemiosmotic mechanism for ATP synthesis is called?

A

oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Protons are pumped across the inner mitochondrial membrane as the net product of this is?

A

3 NADH
1 FADH
1 GTP
2 CO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

The three respiratory enzyme complexes that perform proton pumping, in the order in which they receive electrons are?

A

NADH dehydrogenase complex
cytochrome c reductase complex
cytochrome c oxidase complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Each respiratory enzyme complex contains ______ and other chemical groups that act as stepping stones to facilitate the passage of electrons.

A

metal ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What two things serve as carriers that ferry electrons from one respiratory enzyme complex to another?

A

Ubiquinone and cytochrome C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the net equation for the process of energy conservation?

A

2NADH+O2-> 2NAD+ + 2H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How does NADH dehydrogenase accept electrons from NADH?

A

in the form of a hydride ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What does proton motive force do?

A

pulls H+ back accross the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What makes of the large force in the electrochemical H+ gradient?

A

the membrane potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the large, multisubunit protein embedded in the inner mitochondrial membrane

A

ATP synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

T/F

ATP synthase can operate in reverse, using the energy of ATP hydrolysis to pump protons “uphill” against electrochemical gradient across the membrane

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are F1 and F0 and what do they have to do with ATP synthase?

A

F1 is the stationary head of the multiunit protein

F0 is the rotating portion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

F1 can do what when detatched from the from the F0 part of the complex?

A

carry out the reverse reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

The high energy electrons donated by NADH and FADH after passing along the electron transport chain eventually combine with what?

A

O2 to form H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is much of the energy harnessed from electron transfers along the respiratory chain used to do?

A

Pump H+ out of the matrix

65
Q

What molecules are using symport transportation across the mitochondrial membrane?

A

H+ uses their electrochemical gradient to drive the import of pyruvate and Pi

66
Q

What molecules are using antiport transportation across the mitochondrial membrane?

A

ATP is pumped out and ADP is pumped in depending on membrane potential

67
Q

One glucose oxidation produced about?

A

30 ATP

68
Q

What does poison cyanide do to the inner mitochondrial membrane?

A

Blocks electron transport

69
Q

DNP stands for?

A

2, 4 dinitrophenol

70
Q

What does DNP do?

A

prevents ATP from being made

71
Q

How does DNP prevent ATP from being made?

A

by causing the inner membrane to be permeable to protons, allowing H+ to flow into mitochondrion without passing through ATP synthase so that ATP can no longer be made

72
Q

When bacteriorhodopsin is added to artificial vesicles the protein does what?

A

generates a proton gradient in response to light

73
Q

In artificial vesicles containing both bacteriorhodopsin and ATP synthase the proton gradient created drives?

A

the formation of ATP

74
Q

If an uncoupling agent is present, will ATP be produced?

A

no

75
Q

T/F
Protons in water are highly mobile and electron transfer can cause the transfer of entire hydrogen atoms, because protons are readlily accepted from water or donated to water.

A

True

76
Q

What carries electrons within the lipid bilayer?

A

quinones, one of which being ubiquinone

77
Q

T/F
With each of the three respiratory enzyme complexes, electrons move mainly between metal atoms that are tightly bound to the proteins. Electrons carried between the different complexes by molecules that diffuse alond the lipid bilayer, pick up electrons from one complex and deliver them to another.

A

True

78
Q

_______ are the only electron carriers in electron transport chains that can function without being tightly bound to a protein

A

Quinones

79
Q

what confines ubiquinone to the membrane?

A

it’s long hydrophobic tail

80
Q

Where does ubiquinone pick up electrons from?

A

NADH or FADH2

81
Q

Where does ubiquinone drop electrons off?

A

ctyochrome B-c1 complex

82
Q

T/F
Cytochrome C is a small protein and contains just over 100 amino acids and is held loosely on the outer face of the inner membrane by ionic interaction

A

True

83
Q

___________ is a protein complex that recieves electrons from cytochrome c and donates these to electrons to O2

A

Cytochrome oxidase

84
Q

What two subunits does Cytochrome oxidase contain?

A

I and II

85
Q

When elextrons pass through Cytochrome oxidase to it’s bound O2 molecule, what occurs?

A

The cause the protein to pump protons cross the membrane

86
Q

What two metal atoms does cytochrome oxidase contain?

A

it contains a complex of a heme iron atom juxtaposed with a tightly bound copper atom.

87
Q

What are the two strategies for isloating and organizing different chemical reactions?

A

1-Prokaryotic/Euaryotic aggregate enzymes required to catalyze reactions into large multiponent complexes
2-Eukaryotic- contains them within different membrane enclosed compartments

88
Q

In eukaryotic cells, these membrane enclosed compartments are called?

A

membrane-enclosed organelles

89
Q

The nucleus has what type of membrane?

A

a double membrane known as the nuclear envelope

90
Q

What is the major site for synthesis of new membranes?

A

Endoplasmic reticulum

91
Q

What is the purpose of liver cells?

A

detoxyify alcohol

92
Q

Adrenal glands in the smooth ER do what?

A

produce new steroid hormones

93
Q

What does the smooth ER have to do with muscle cells?

A

it sequesters Ca2+ from the cytosol and the release of Ca2+ to cytosol triggers secretion of signal molecules and the contractions of muscle cells

94
Q

What does the Golgi Apparatus do?

A

recieves proteins and lipis from the ER, modifies them, and then dispatches them to other destinations

95
Q

Lysosomes perform what function?

A

small sacs of digestive enzymes degrade worn-out organelles as well as macromolecules taken into the cell by endocytosis

96
Q

What are peroxisomes?

A

small organelles containing a single membrane that break down lipids and destroy toxic molecules

97
Q

In one hepatocyte, what are the # of mitochondria, ER, nucleus, golgi and cytosol?

A

1700 Mitochondria

1 of everything else

98
Q

How did nuclear membranes and the ER thought to evolve?

A

by and invagination of the outer plasma membrane

99
Q

How was mitochondria thought to evolve?

A

Mitochondria was actually thought to be it’s own seperate cell, which was engulfed by larger eukaryotic cell

-chloroplasts were thought to have evolved the same way

100
Q

What are the three mechanisms for import of protein?

A

1) Transport through nuclear poer
2) Transport across membrane
3) Transport by vesicles

101
Q

What is a sorting signal?

A

directs the protein to the organelle in which it is required. Proteins that lack such signals remain in the cytosol

102
Q

How does transport through nuclear pores work?

A

proteins move from the cytosol into the nucleus are transported through the pores than penetrate the inner and outer nuclear membrane

103
Q

Where does a import signal begin?

A

It begins at the N-terminus

->However, if the protein needs to STAY in the ER, it has a short sequence on the very end that keeps it there

104
Q

T/F

The outer nuclear membrane is continuous with the ER membrane

A

True!

105
Q

How many proteins is the nuclear pore composed of?

A

30

106
Q

What helps ‘guide’ proteins through the nuclear pore?

A

the meshwork pattern on the inside of the nuclear pore

107
Q

T/F the nuclear pores are large enough to accept protein in fully folded conformation

A

true

108
Q

After a protein has passed through the nuclear pore, what “catches” the protein?

A

a basket like structure made of protein fibrils

109
Q

What is a nuclear localization signal?

A

the signal sequence that directs a protein from the cytosol into the nucleus typically consisits of one or two short sequences contaiing several positively charges lysine or arginines

110
Q

What binds to the nuclear localization sequence on newly synthesized proteins?

A

Nuclear transport receptors

111
Q

What do nuclear transport receptors do?

A

guide the protein through the nuclear pore into the nucleus

112
Q

When the protein has been delivered inside of the nucleus, what happens to the nuclear transport receptor?

A

it is returned to the cytosol via the nuclear pore for reuse

113
Q

Energy derived from _______ ________ drives nuclear transport.

A

GTP hydrolysis

114
Q

What binds to the nuclear transport receptor inside of the nucleus that causes it to release it’s cargo?

A

Ran-GTP

115
Q

Once the nuclear transport receptor has passed through the pore and is back in the cytosol, what occurs?

A

an accessory protein triggers Ran to hydrolyze its bound GTP to GDP. Then Ran-GDP falls off the nuclear transport receptor where it is free to bind with another cargo protein

116
Q

T/F

Proteins are imported into mitochondria in unfolded form

A

true

117
Q

Give the steps for the import of a protein into the mitochondria-

*hint: 4

A

1) Mitochondrial signal sequence of the precursor protein is recognized by receptor located on outer mitochondrial membrane
2) Complex of receptor and protein diffuses laterally in the membrane on a contact site
- protein on contact sight is translocated across both membranes by a protein translocator
3) Signal sequence is cleaved by signal peptidase
4) Chaperone proteins help to pull protein across the membrane

118
Q

Chaperone proteins help to pull protein across membrane, why is this needed?

A

They help pull protein across membrane so that no “backpeddling” occurs in through the transporter

119
Q

The __________________ __________ has the most extensive membrane network in eukaryotic cells

A

endoplasmic reticulum

120
Q

What are attached to the cytosolic side of the ER membrane and are making proteins that are translocated to the ER?

A: mRNA
B:Membrane-bound ribosomes
C: SRP complexes
D: Free ribosomes

A

B-Membrabe-bound ribosomes

121
Q
What are unattached to any membrane and are making all of the other proteins encoded by the nuclear DNA
A: mRNA
B:Membrane-bound ribosomes
C: SRP complexes
D: Free ribosomes
A

D: Free ribosomes

122
Q

How is a polyribosome formed?

A

many ribosomes bind to each mRNA molecule

123
Q
What are the two components that direct a ribosome to the ER membrane?
A: mRNA
B:ER signal sequence 
C: SRP complexes
D: Free ribosomes 
E: Both B and C
A

Both B and C
B:ER signal sequence
C: SRP complexes

124
Q

A SRP complex stands for?

A

Signal Recognition Particle

125
Q

_________ binds to the exposed ER signal sequence and to the ribosome, thereby slowing protein synthesis by the ribosome

A

Signal Recognition Particle

126
Q

After a Signal Recognition Particle binds to the exposed ER signal sequence and to the ribosome, thereby slowing protein synthesis by the ribosome, what occurs?

A

The SRP-complex binds to an SRP receptor in the ER membrane

127
Q

After the SRP-complex binds to an SRP receptor in the ER membrane, what occurs?

A

The SRP is released, passing ribosome to a translocation channel in ER membrane

128
Q

After a ribosome is placed by the SRP into a translocation channel, the translocation channel does what?

A

inserts the polypeptide chain into the membrane and starts to transfer it across the lipid bilayer

129
Q

During the translocation process of the translocation channel, the signal sequence is?

A

cleaved from the growing protein by a signal peptidase

130
Q

Translocation channels in the ER transport the protein across the lipid bilayer in what formation?

A

a loop like formation

131
Q

What occurs to the cleaved signal sequence after the protein is translocated?

A

it is ejected into the bilayer

132
Q

T/F

A single pass transmembrane protein is retained in the lipid bilayer

A

True

133
Q

Transmembrane proteins contain what two components that allow them to be integrated into the ER membrane?

A

a N-terminus ER signal sequence and a hydrophobic stop-transfer sequence

134
Q

T/F

A double pass transmembanse protein uses an internal start-transfer sequence to integrate into the ER membrane

A

True

135
Q

Double pass transmembrane proteins form what structure in the ER?

A

a loop like structure within the lumen and free ends within the cytosol

136
Q

Cleavage of signal sequences occur in all translocated proteins except?

A

single and double pass proteins

137
Q

What are the Eukaryotic membrane-enclosed organelles?

A

ER, Golgi, lysosomes, endosomes, mitochondria, and peroxisomes

138
Q

T/F

Proteins that remain in the cytosol have a cytosol signalling sequence

A

FALSE—> since most proteins are made in the cytosol, cytosolic proteins don’t have a signaling sequence, since they are already located in their final destination

139
Q

T/F

Mitchondrial proteins must be unfolded to allow them to pass through the mitochondrial membrane

A

True!

Only nuclear pores are big enough to allow fully folded confirmations through

140
Q

Soluble proteins destined for secretion for for the lumen of an organelle pass?

A

completly into the ER lumen

141
Q

What carries soluble protein and membrane between cell compartments?

A

transport vesicles

142
Q

outward Secretory Pathway is also known as?

A

Exocytosis

143
Q

inward secretory pathway is also known as?

A

Endocytosis

144
Q

In the outward Secretory Pathway what is the order which the protein travels?

A

ER>golgi>plasma membrane

145
Q

In the inward Secretory Pathway what is the order which the protein travels

A

Plasma membrane>lysosomes

146
Q

_______ forms basket-like cage that helps shape membranes into vesicles

A

Clathrin

147
Q

What is the structure of Clathrin?

A

a three pronged structure

148
Q

Before Clathrin can create it’’s cage like structure, what must first occur?

A

Adaptins capture the cargo receptors with their bound cargo molecules

149
Q

What proteins assemble around neck of budding vesicles, hydrolyze their GTP and pinch off the vesicle

A

dynamin

150
Q

Rab proteins are located on the surface of vesicles, and bind to ___________ ________ ____________ that allows the vesicle to dock on its target membrane

A

filamentous tethering protein

151
Q

After Rab proteins bind with the filamentous tethering proteins, a ________ on the vesicle binds to a complementary ______ on target membrane.

A

v-snare

t-snare

152
Q

T/F

Rab and tethering proteins provide the inital recognition between a vesicle and its target membrane, the pairing of complementary SNAREs also helps ensure that transport vesicles reach their appropriate target membrane.

A

True

153
Q

T/F

SNARE proteins play a central role in membrane function

A

True

154
Q

What squeezes out any water molecules between the two membranes, allowing their lipid to flow together to form a continous bilayer

A

The force of the SNARE winding together

155
Q

An oligosaccharide is a?

A

multiple sugar unit

156
Q

The most common linkage on a glycoprotein is?

A

N-linked oligosaccharide side cahains

157
Q

T/F

Chaperones prevent misfolded or partially assembled proteins from leaving ER

A

True

158
Q

Misfolded proteins bind to receptors that stimulate the production of?

A

a transcription regulator

159
Q

unfolded protein repsonse is?

A

the transcription regulators that are activated when a misfolded protein occurs that activate genes in the nucleus that encode chaperones and other ER components, thus promoting the proper folding and processing of proteins.