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Unformatted text preview: free solution. In cytoskeleton-rich
r egions, size limit was even smaller.
significance: cytoskeleton mediates transport of vesicles from ER to Golgi Major Fibr ous Polymers of the Cytoplasm:
* microtubules (24 nm diameter): composed of polymerized alpha-beta tubulin dimer s and
associated binding proteins
* intermediate filaments (10 nm diameter ) polymerized IF subunits and associated binding pr oteins
* actin/micr ofilaments (7 nm diameter) polymer ized globular (G)-actin and associated binding
* actin filaments and Mts are polarized polymer s; Ifs ar e apolar
* actin/MT polarity is a cr itical pr operty w ith respect to functions for these polymer s both with
r espect to assembly/disassembly driven processes and molecular motor dependent pr ocesses Intermediate filaments cour se out fr om surface
Microtubules extend out fr om a perinuclear MT or ganizing center : the centr osome
Epithelial cells: actin filaments
Mixed polarity "contractile" r ing of fi...
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- Fall '13