chapter eighteen Flashcards
what are networks of protein filaments that extend through the cell, which organize, give shape and do work
cytoskeleton
what are the three filament systems
intermediate, microtubules, and actin
microtubules and actin are _____ and ______
dynamic, polarized
this cytoskeleton system has great tensile strength, form network of filaments that surround nucleus and extend to plasma membrane
intermediate
the ____ is the assembly subunit of the intermediate filament
tetramer
keratin, nuerofilaments, nuclear lamins
intermediate filaments
associates with the nuclear pore complex and chromatin
nuclear lamina (intermediate filaments)
mutation in nuclear lamina, premature aging disease
progeria
_____ are crucial for all eukaryotic cells, organize the organelles in the cytoplasm
microtubules
______ for the mitotic spindle
microtubules
_____ assemble into cillia and flagella, function depends on motor proteins
microtubules
_____ assemble from alpha-beta tubulin dimers, 13 protofilaments (polarized structures)
microtubules
microtubules: alpha is exposed at ____ end and beta is exposed at ____ end
minus, plus
_____ are microtubules organizing centers
centrosomes
a pair of _____ are within the centrosome
centrioles
individual microtubules grow and shrink in a process called ____ _____
dynamic instability
dynamic instability of microtubules is driven by ____ _____
GTP hydrolysis
Tubulin binds ____ and after a time delay it hydrolyzes ____ to _____
GTP, GTP to GDP