Term
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Definition
- Rope-like polymer
- Mechanical strength
- ex: keratin and nuclear lamina
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Term
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Definition
| Cytoplasmic intermediate filament that provides toughness to skin |
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Term
| Two categories of intermediate filaments |
|
Definition
(1) cytoplasmic
(2) nuclear |
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Term
| Cytoplasmic Intermediate Filaments |
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Definition
Anchor to neighboring cells via desmosome and basal lamina via hemidesmosomes
ex. keratin |
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Term
| Epidermolysis bullosa simplex (EBS) |
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Definition
Rare mutation of keratin genes which interferes with keratin assembly in the epidermis
Skin highly vulnerable to mechanical stress--blisters |
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Term
| Nuclear Intermediate Filaments |
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Definition
Made of nuclear lamins
Found just beneath the inner nuclear membrane
ex. nuclear lamina |
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Term
| Nuclear Lamina Intermediate Filament |
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Definition
Found beneath inner nuclear membrane
ex. nuclear lamina |
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Term
Amylotrophic Lateral Sclerosis (ALS)
Lou Gehrig's Disease |
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Definition
Believed to be a neurofilament mutation which leads to an abnormal accumulation and assembly of neurofilaments in motor neurons
Leads to muscle atrophy, paralysis, and death
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Term
| Assembly of Intermediate Filaments |
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Definition
| dimer of polypeptides forming a coiled coil-->tetramer-->protofilament-->rope-like structure that is cross-linked for strength |
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Term
|
Definition
Hollow tubes made of 13 protofilaments
alpha and beta tubulin heterodimers
Dynein, kinesin, |
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Term
| Functions of Microtubules |
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Definition
(1) Organization and polarization of cells
(2) Intracellular transport-dynein and kinesin
(3)Mitotic spindle
(4) Cilia and flagella- dynein motor protein |
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Term
| Microtubule Capping Proteins |
|
Definition
Found close to PM
Prevent disassembly of microtubules and encourage cell polarization |
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Term
|
Definition
| Microtubule motor protein moves towards negative end of filament |
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Term
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Definition
| Microtubule motor protein moves to positive end of filament |
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Term
|
Definition
Absence of dynein in flagella and cilia--immobile
Male sterility
Chronic respiratory infection |
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Term
|
Definition
Anticancer drugs
Bind free tubulin and prevent polymerization |
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Term
|
Definition
Anticancer drug
Binds polymerized MT arresting cells in mitosis |
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Term
|
Definition
Anti-gout/arthritis
Binds free tubulin in macrophages inhibiting their abilty to phagocytize |
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Term
|
Definition
Strucural polarity
GTP bound to Beta tubulin promotes assembly
GTP hydrolyzes faster than can add more GTP-beta tubulin dimers results in disassembly of tubule |
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Term
|
Definition
| New GTP added faster than can hydrolyze--do not shrink |
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Term
Actin Filaments
Microfilaments |
|
Definition
Polymerization of G actin monomers to form dimers or trimers which group to form an F-actin filament
Have polarity
Motor proteins |
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Term
|
Definition
(1) Support cell surface protrusion (actin bundles and networks)
(2) Actin motor proteins (myosin I and II)
(3)RBC cell cortex--crosslink with spectrin |
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Term
|
Definition
Two types:
Parallel
Network |
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Term
|
Definition
Fibrin crosslink
Support microvilli and filopodia |
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Term
|
Definition
| Crosslinker for parallel actin bundles |
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Term
|
Definition
Alpha actin crosslink
Support stress fibers and focal adhesions |
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Term
|
Definition
| Crosslink contractile actin bundles |
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Term
|
Definition
Filamin crosslink
Support lamellae and cell cortex
Gel-like |
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Term
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Definition
| Crosslink for network actin structures |
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Term
|
Definition
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Term
|
Definition
Intracellular transport
ATPase activity |
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Term
|
Definition
Muscle contractions
ATPase activity
Myofibrils: myosin moves along actin |
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Term
|
Definition
2-D cortical cytoskeleton in RBC
Crosslinked with actin
Determines biconcave disc shape, strength, and flexibility |
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Term
|
Definition
Property of actin (and microtubules)
Continuously add to (+) end and continuously take away from (-) end
Steady state behavior (not equilibrium)
Requires ATP hydrolysis |
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