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13 Cards in this Set
- Front
- Back
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What is "treadmilling" of actin subunits?
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Subunits add much more readily to (+) end, and are lost more readily at (-) end.
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How are actin filaments organized?
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1. Meshworks
2. Bundles a. contractile bundles b. microvilli |
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What can muscular dystrophy be traced to?
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Breaks in the cell membrane associated with defective dystrophin/meshwork linkage.
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What do MAPs do?
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Microtubule=associated proteins bind to outer surface of the MT and control MT structural organization or operate like motors to effect movement of MTs or associated vesicles.
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How are Microtubules anchored to the MTOC (microtubule organizing center)?
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(-) ends at MTOC, radiate out to periphery of cell and (+) ends terminate freely in periphery.
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What are the functions of Intermediate filaments?
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Provide structural scaffolding inside the cell - no known role in motility.
-Toughen epithelia -Support junctional complexes -Maintain cell shape,s upport organelles, support axons )in conjunction with MTs) |
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What are five important types of IMFs and where are they found?
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1) Keratin - epithelial cells
2) Vimentin - mesenchymal (typically connective tissue) 3) Desmin - muscle 4) Neurofilaments - nerve axons 5) Nuclear lamins - nuclear env |
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How are IMFs anchored?
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Anchored by attachments to the nuclear envelope and the plasma membran (desmosomes and mehidesmosomes).
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What is the Basal Lamina?
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Support layer where junctions are attached.
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What are the 5 types of junctions found in an epithelial cell?
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1) Tight
2) Adherens (Adhesion) 3) Desmosome 4) Gap 5) Hemidesmosome |
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What are the two types of adhesion junctions?
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1) Focal
2) Belt - actin filament bundles contain myosin |
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What is the difference b/n desmosomes and hemidesmosomes?
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Desmosomes use transmembrane proteins to anchor IFs that are in the cadherin family, whereas hemi's proteins are integrins.
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To what ends (+, -) do kinesin and dynein move vesicles along MTs?
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Kinesin moves vesicles towards (+) ends, dynein towards (-) ends.
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