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17 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is the major subunit of microtubules?
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Actin
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thin filaments
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What are the 3 types of cytoskeleton proteins?
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Intermediate Filaments - rope-like fibers, assembly regulated by phosphorylation, protect from mechanical stress
Microtubules - hollow cylinders composed of tubulin, originate from MTOC, assembly by GTP hydrolysis, aid in vesicle and organelle movement, axonal transport, cell division, comprise cilia and flagella Microfilaments - composed of actin, important for cell locomotion and muscle contraction |
if mt mf
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Where do the forces, that move the cell forward, generated?
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cortex
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What pushes forward the leading edge of a lamellipodium?
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-assembly of an actin network
-actin polymerization at this leading edge of the cell pushes the plasma membrane forward and forms new regions of actin cortex |
thin
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What is the surface that the cell crawls on?
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substratum
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What is the leading edge of the cell called? Describe it.
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lamellipodium: sheet-like, contains dense meshwork of actin filaments, oriented so that most of the filaments have their plus ends close to the plasma membrane
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What do the focal contacts contain?
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integrins
(transmembrane proteins in their plasma membrane) adhere to molecules in the extracellular matrix or on te surface of another cell over which the moving cell is crawling |
transmembrane proteins in their plasma membrane
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What draws the rear end of the cell forward?
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contraction
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What is the filopodia?
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extend from the cell, thin/stiff protrusions both at leading edge and elsewhere on the surface
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What is an ARP?
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Actin related protein that promotes the formation of branched actin filaments. these proteins form a complex that binds to the existing actin filaments where they nucleate the growth of a new filament which grows out at an angle to form a side branch (formn of 2d actin web). With additional help of actin-binding protens (capping proteins etc) help to push the lamellipodia forward. (mediates nucleation of new actin filaments)
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What protects the actin filament plus ends (preventing further assembly or disassembly from old plus ends at the front of the array)?
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Capping proteins
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--- proteins
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Depolymerizing protein?
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hydrolysis of ATP bound to polymerized actin subunits promotes depolymerization at the rear end of the actin complex
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What are cell locomotion and shape changes important for?
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wound healing
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healing of ...
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What regulates the arrangement of actin filaments?
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GTP binding proteins (Rho protein binding family) which affect the arrangement of actin filaments in different ways (Cdc42-triggers actin polymerization and bundling to form the filopodia , Rac GTP-binding protein-promotes formation sheetlike lamellapodia formation)
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rho family
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Cdc42
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triggers actin polymerization and bundling to form filopodia
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triggers actin polymerization and bundling to form ... ?
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Rac
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promotes sheetlike lamellapodia formation
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What is the motor protein for actin?
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Myosin
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