Test 4 Flashcards
(132 cards)
1
Q
_____ bud from RER with no ribosomes.
A
Vesicles
2
Q
What is an organelle that is surrounded by a double membrane?
A
Autophagy
3
Q
What are the roles of phagocytosis?
A
Uptake of large food particles by single celled organisms. Uptake and destruction of pathogens in animals.
4
Q
The 3 major steps in phagocytosis include:
A
1 Plasma membrane folds enclose the food or pathogens.
- The folds fuse to produce a vacuole or phagosome that pinches off inwardly.
- Phagosomes fuse with a lysosome and the material is digested.
5
Q
In the Cisternal Maturation Model, Golgi enzymes are carried in a _____ direction in what? While Cargo is moved ___ and is what?
A
retrograde, transportation vesicles; in and is restricted to cisternae.
6
Q
What is a family of small GTP-binding proteins that specifically tether vesicles to targets by recruiting tethering proteins?
A
Rabs
7
Q
_____ constitute a family of more than 35 membrane proteins.
A
SNAREs
8
Q
The toxins responsible for ______ and ____ act as proteases whose only known substrates are specific SNAREs.
A
botulism and tetanus
9
Q
Cleavage of the SNAREs that are specific to boulism and tetanus prevent the ___________ and ___________. Both toxins cause paralysis and cause death.
A
fusion of vesicles, release of neurotransmitters
10
Q
a lipid carrier molecule on which oligosaccharides are assembled prior to transfer to specific asparagine residues on ER membrane proteins
A
Dolichol Phosphate
11
Q
The sequence of Dolichol Phosphate sugars depends on the sequence of _________ that participate in making the oligosaccharide and the location of the specific enzymes within the membranes of the secretory pathway.
A
glycosyltransferases
12
Q
During Glycosylation in the Golgi Complex, most ________ are removed and ____ are added sequentially by glycotransferases as in the ER.
A
mannose residues, sugars
13
Q
Sugars added during Glycosylation in the Golgi Complex are added to the ______ attached to the ______.
A
oligosaccharide, polypeptide
14
Q
Glycosylation in the Golgi Complex occurs as the ___________.
A
polypeptide moves through the stacks
15
Q
What can result due to Glycosylation in the Golgi Complex?
A
Varied oligosaccharides
16
Q
The Golgi complex is the site of Glycosylation and the ___________ including glucosaminoglycan chains of proteoglycans, pectins and hemicellulose.
A
synthesis of complex carbohydrates
17
Q
______ move materials from the ER “forward” to the ERGIC (ERG intermediate complex) and Golgi complex.
A
COPII-coated vesicles
18
Q
COPI-coated vesicles move materials in a ______ direction from the Golgi complex to the ERGIC and ER, and from the Trans Golgi cisternae to the cis cisternae.
A
retrograde
19
Q
________ move materials from the TGN to endosomes, lysosomes, and vacuoles.
A
Clatherin-coated vesicles
20
Q
For maintenance of organelle membrane proteins, ________ are excluded from transport vesicles.
A
Resident proteins
21
Q
_____ are short amino acid sequences that bind receptors which capture the protein and return them to the ER in COPI-coated vesicles.
A
Retrieval sequences
22
Q
_____ consists of three light and three heavy chains joined to form a three legged triskelion. Each leg of the triskelion extends along two edges of a polygon.
A
Clathrin
23
Q
Each leg of clathrin ends in a ____________ where it engages an adaptor.
A
hook that projects toward the surface
24
Q
The adaptor at the end of a clathrin leg is a __________ that attaches to the _____.
A
transmembrane protein, lignin
25
With this disease, patient’s contain lysosomes bloated with undigested materials. Due to an N acetyl glucosamine phosphotransferase deficiency. The enzyme places a mannose-6phosphate “address” on lysosomal proteins.
I-cell disease
26
These disorders are due to a lac of a single lysosomal enzyme causing undigested substrate to accumulate.
Lysosomal storage disorders
27
____ is a Lysosomal storage disorder due to a deficiency in β-N-hexosaminidase. This enzyme digests a major lipid componet of the membranes of brain cells.
Tay-Sachs
28
Gaucher's disease is a Lysosomal storage disorder due to
glucocerebroside lipids accumulating in macrophages.
29
_____ is involved in Gaucher's disease, the gluycocerebrosidase with mannose residues is removed, so the enzyme goes to macrophages not the liver cells.
Enzyme replacement therapy
30
A ______ protein on a vesicle interacts with a _____ on the target membrane forming a four stranded α-helical bundle that brings the two membranes into contact.
v-SNARE, t-SNARE
31
_____ proteins pull two membranes together with enough force to fuse the membranes.
SNARE
32
Lysosomal proteins are synthesized on ___________, and carried to the _______.
ribosomes of RER, Golgi complex
33
Lysosomal proteins are recognized by _____ in the _______, which add a phosphate group to a mannose residues.
enzymes, Golgi cisternae
34
Only _______ enzymes possess phosphorylated mannose residues, so they act as recognition signals.
lysosomal
35
_______ are integral membrane proteins in the TGN that forms clathrin-coated vesicles
Mannose 6-phosphate (MPR) receptors
36
GGAs are a family of _____ that are adaptors which connect the clathrin protein with the sorting signal. The _______is released and the uncoated vesicle moves on to its destination.
proteins, clathrin coat
37
A ______ forms a collar around the coated pit of a clathrin just before it pinches off.
dynamin ring
38
Lysosomes play a roll in intracellular digestion by _________ or _______.
single-celled organisms or phagocytes
39
The outer membrane of an autophagy fuses with a ____ to replace old organelles, or cannibalize. __________ build up in cells may play a role in aging.
lysosome, Lipofuscin granules
40
Lysosomes provide protection against _______ like abnormal protein aggregates or bacteria.
intracellular threats
41
Cholesterol enters a cell by ____ binding to LDL receptors in a coated pit, the pit invaginates to form a _____ _____, the clathrin coat is ______ and the ______ are recycled back to the plasma membrane while the _______ is delivered to lysosomes, de-esterfied and used by the cell.
LDL, coated vesicle, disassembled, LDL receptors, cholesterol
42
Plat vacuoles store ____, ____, ____ ___, ____, _____, and ____. They also store ____ ___ as defense against fungi or herbivores.
ions, sugars, amino acids, proteins, polysaccharides, and pigments.
toxic compounds
43
_________ in plant vacuoles is produced by ion pumps followed by osmosis. It provides support for soft tissues and stretches the cell walls during cell growth.
Turgor pressure
44
What are the 3 roles of chaperones?
Prepare polypeptides for uptake, Direct them to the OMM, and Move them through the IMM.
45
A chaperone uses energy from ATP to pull the polypeptide through the pore, this is known as what?
Force-generating Action
46
A chaperone binds to the polypeptides as they start through the pore, preventing them from moving back out. Continued binding ratchets the polypeptide through. This process is known as?
Biased diffusion Action
47
_______ are long, hollow, unbranched tubes composed of tubulin. ______and ______are motor proteins that work with microtubules.
Microtubules, Kinesins and dyneins
48
________ are solid thinner structures, often organized into a branching network. They are composed of actin. _____ are motor proteins that work with microfilaments.
Microfilaments, Myosins
49
Microtubules are composed of ____ while microfilaments are composed of _____.
tubulin, actin
50
_______ are tough, rope-like fibers, composed of a variety of related proteins. They have no motor proteins.
Intermediate filaments
51
Though microtubules, microfilaments, and intermediate filaments are all made of proteins, which are made of motor proteins and which have no motor proteins?
Microtubules and microfilaments are made of motor proteins.
| Intermediate filaments do not have motor proteins.
52
Each type of ____________ is a polymer of protein subunits, held together by weak, noncovalent bonds, are able to rapidly assemble and disassemble, and are found in animal cells.
cytoskeleton filament,
53
____ do not need intermediate filaments because why?
Plants don’t need intermediate filaments because they have cell walls for structure.
54
______________ uses fluorescently labeled cytoskeletal subunits injected into cells showing the dynamic changes in length of tubules and orientation of filaments.
Fluorescent microscopy
55
_____________ where microtubules attach to glass coverslips and beads, then ATP is added and video cameras observe movement of the beads along the tubules. Focused laser beams trap single beads to measure motor force.
In vitro motility assays
56
_____________ with altered gene expression have specific defects suggesting a role for the protein. Ex: fragmented Golgi complexes suggest motor protein plays role in positioning Golgi complexes.
Knockout mice
57
What are the 3 functions of the cytoskeleton and what is it involved in?
Dynamic scaffold providing shape of cell, Positioning organelles, Move materials and organelles within cells, Move cells, Involved in cell division
58
What are the 6 functions of microtubules?
Cell division, Cell movement, Mechanical support, Move enzymes in plasma membrane, Maintains the organization of cell’s internal structure, positioning organelles
Intracellular motility of macromolecules and organelles
59
A function of microtubules is cell division, what does it divide?
chromosomes
60
Microtubules are important for cell movement. What makes this possible?
Cilia and flagella
61
Axonal transport uses two motor proteins. What are they?
Kinesin and dynein
62
______ moves vesicles and organelles out (anterograde direction) while _______ moves vesicles and organelles inward to the cell body (retrograde direction).
Kinesin, Dynein
63
What are the Microtubule Organizing Centers (MTOC) of animals? They are a complex of two barrel-shaped centrioles surrounded by a complex pericentriolar material (PCM).
Centrosome
64
Centrioles contain ___ evenly spaced sets of ___ microtubules. Microtubules initiate from the ___ not the _____, the minus end of the tubules is associated with the centrosome. Some microtubules separate from the PCM.
nine, three, PCM, centrioles
65
What are identical structure to centrioles and give rise to each other? They give rise to cilia and flagella too.
Basal bodies
66
In plants microtubules arise around the ______ and throughout the _____.
nucleus, cortex
67
Where are microtubules formed? Where is their organization center?
Pericentriolar material, Centrosome
68
What binds to the B-tubulin subunit and is required for assembly of tubulin dimers.
GTP
69
What incorporates into the end of the microtubule?
GTP-dimers
70
The growing plus end of microtubules is an _______ that facilitates rapid growth. _______ is accompanied by hydrolysis of bound GTP to bound GDP.
open sheet, Closure
71
When are GDP-tubulin subunits are less stable?
in the straight protofilament arrangement.
72
Microtubules are (shape). Intermediate filaments are ____ that form a ____.
globs, linear, tetramer
73
What holds the microtubule together?
Microtubule associated proteins (MAP)
74
Without ____ protofilaments curl outward undergoing catastrophic depolymerization and the microtubules disassemble.
MAPs
75
The plus end of the microtubule can change between growing or shortening. This is known as what?
This provides a mechanism for microtubules to rapidly explore the cytoplasm for appropriate attachment sites.
Dynamic instability
76
_____ are proteins that bind to the plus end regulating rate of growth and shrinkage.
TIPs
77
____ is an anticancer drug. It binds to the microtubule polymer, inhibiting its disassembly, thereby preventing the cell from assembling new microtubule structures.
Taxol
78
Taxol can be used in chemotherapy because it preferentially kills tumor cells. Cancer cells die due to ________________ that prevent cells from dividing in the presence of the drug.
their lack of normal check points
79
Kartagener syndrome effects mostly ____. Bardet-Biedl syndrome effects ____, and the ____.
males (sperm), limbs and the body
80
______ is caused by mutations in the assembly of basal bodies and cilia.
It demonstrates the importance of these organelles in development and function.
Bardet-Biedl syndrome
81
Which disease has more symptoms? Kartagener syndrome or Bardet-Biedl syndrome
Bardet-Biedl syndrome
82
Cilia work like ____. They remain _____ during a power stroke and ____ for the recovery stroke while
two flagella can ____ like a breast stroke or _____ like a sperm.
oars, rigid, flexible, pull, push
83
_____ is an ATPase with its stem attached to the surface of an A-tube with its arms projected toward the B-tube of the next doublet. During a power stroke, arms attach to the B-tube, the dynein molecule undergoes a conformational change, causing one doublet to slide along the other. Arms detach and reattach.
Ciliary dynein
84
Sliding alternates from one side of the flagella to the other, so the flagella ________.
bends one way then the other
85
_____________ are important in tissue-specific functions
Intermediate filaments
86
What are found only in animals, giving strength to neurons, muscle cells, and epithelial cells that line the body’s cavities?
Intermediate filaments
87
Aggregation of neurofilaments may block axonal transport, leading to the death of affected neurons. Aggregation of neurofilaments is seen in ___ and _________.
ALS and Parkinson’s disease
88
An intermediate filament's basic unit is a ____ that forms a _____.
dimer, tetramer
89
Unlike microtubules, new tetramers of intermediate filaments are incorporated into the _____________.
filament’s interior
90
Like microtubules, filament assembly and disassembly is in _______ controlled by phosphorylation and dephosphorylation.
dynamic equilibrium
91
During actin filament assembly, actin monomers bind to what?
ATP
92
During actin filament assembly, after monomer incorporation the ATP is ______.
hydrolized
93
During actin filament assembly, initiation is _____, while elongation is ____.
slow, fast
94
During actin filament assembly, the ____ end grows faster than the _____ end.
plus, minus
95
At high monomer concentration, during actin filament assembly, ____ ends grow, at low concentration _______ end grows, at very low concentration the ______ grows while the ______ shortens.
both, only the plus, plus end, minus end
96
What are the 5 functions of actin filaments?
Cell movement, Growth of axon, Movement of vesicles, Phagocytosis, Cytokinesis
97
motors that move over actin filaments in the plus direction. A two motor head binds actin and hydrolyzes ATP to drive the myosin motor. Function in muscle contraction and cytokinesis.
Conventional Myocin II
98
one of two motor heads remains attached as the other head walks over the first. Myosin V neck is 3X longer than that of myosin II, so it can take very long steps.
Unconventional Myosin V
99
______ and _____ evolved from the same protein in an ancestral prokaryote.
Myosins and Kinesins
100
________ is due to a defective myosin Va or Rab27a gene, melanosomes can not move into hair follicles.
Griscelli Syndrome
101
_____ and _____ may be bound together with unconventional myosin so vesicles or organelles may move along microtubules, and switch to microfilaments.
Kinesins and cytoplasmic dynein
102
_____ are the outer light stained areas of actin filaments.
I bands
103
______ is the inner dark staining area of both actin and myosin.
A band
104
_____ is the inner area of myosin.
H zone
105
During muscle contraction the ________ and _______ become shorter, while the ______ remains about the same.
I band and H zone, A band
106
Sarcomere Structure =
contractile units
107
The following are _____: nucleating proteins, monomer,
actin binding proteins
108
initiate the formation of an actin filament.
Nucleating proteins
109
prevent all of the monomers in the cell from being polymerized.
Monomer – sequestering proteins
110
cap either end of the filament preventing the addition or deletion of monomers.
End blocking proteins
111
promotes the growth of actin filaments.
Monomer-polymerizing protein
112
promote depolymerization, rapid turnover of actin, essential for cell locomotion, phagocytosis and cytokinesis.
Actin filament depolymerizing proteins
113
can cross link two or more filaments to produce 3-D elastic gels or parallel arrays.
Cross-linking proteins
114
can break a filament into producing free ends for growth or may cap them.
Filament-severing proteins
115
peripheral membrane proteins that aid actin in phagocytosis and cytokinesis
Membrane binding proteins
116
These are components of what?Two membranes, Nuclear pores, Outer membrane is studded with ribosomes, Integral membrane proteins, Nuclear lamina
Nuclear Envelope
117
Where do nuclear-membranes are fused together?
at the pores
118
Proteins and RNAs are targeted to move across the nuclear-envelope by transport receptor proteins called ________ and ________.
importins and exportins
119
This disease is due to a silent mutation in Lamina A that produces an extra intron splicing site. (makes kids look like old people)
Hutchinson-Gilford progeria
120
a Chromosomal Aberration in which the cell still has all the DNA, usually does not affect somatic cells, results in nonviable zygotes. Cuts in two places.
Inversions
121
a Chromosomal Aberration in which the cell still has all the DNA. It usually does not affect somatic cells, results in non-viable zygotes. Increases chance of cancer. Part or all of one chromosome attaches to another. *Played a role in the evolution of humans. Chimpanzees, gorillas and orangutans have 24 pairs of chromosomes.
Translocations
122
a Chromosomal Aberration in which a part of a chromosome is missing. Most zygotes do not develop to term. Ex: Cri-du-Chat syndrome results from a deletion of chromosome 5, causing a defect in the larynx.
Deletions
123
a Chromosomal Aberration in which extra copies of some genes causing serious negative effects
Duplication
124
Somatic cells are ______ cells.
normal body
125
_______ are used to screen individuals for chromosomal abnormalities. They are routinely prepared from cultures of blood cells, anionic fluid, placenta, fetal tissue and bone marrow.
Karyotypes
126
What does lethal mean?
It means a viable zygote will not be produced.
127
_______ follow chromosome breakage, which can be caused by viral infection, X-ray, O2 reactive chemicals, or some genetically inherited diseases.
Chromosomal aberrations
128
Aberrations that occur in somatic cells usually have minor effects, but can lead to ________.
cancer
129
Aberrations in gametes are usually _____.
lethal
130
repeating subunits of histone proteins wrapped by DNA, forming the lowest level of chromatin organization.
Nucleosomes
131
Nucleosomes are organized into fibers which are organized into looped domains. This is called what?
Higher level organization
132
What is the linker histone and is needed to coil the nucleosomes into fibers in higher level organization.
Histone type H1
