lecture 9 Flashcards
name 3 ways f-actin can be organised
dynamic cross-linking
cross-linked
ordered bundling
what are microtubules made of
tubulin dimers
a and b tubulin molecules are subunits of protofilaments
what process occurs at the plus end of the microtubule polymer
polymerisation
GTP-bound tubulin dimers are added and hydrolyse GTP to GDP
what stabilises the growing polymer
a cap of GTP tubulin and the GTP cap disappears
what is ‘pausing’
when polymerisation slows down as there is not enough tubulin
when does depolymerisation of the microtubule occur
when it becomes unstable
what is a ‘catastophe’
the moment of transition of a microtuble in depolymerisation
what is dynamic instability
constant slow growth and rapid shrinkage of microtubules
what is a ‘rescue event’
moment of transition in polymerisation
what does speckle microscopy reveal
differences in dynamic behaviour of F-actin and microtubules
actin: Incorporated actin treadmills
through the actin filament meshwork
microtubules: Microtubule ends are dynamic,
while incorporated tubulin
remains relativley stationary
what do microtubules binding proteins do
modify microtubule organisation and function
features of centrioles
consist of mainly microtubule
become the basal body of flagella and cilia
centrioles organise the peri-centriolar material (PCM)
replicate during the cell cycle
what does the centrosomes consist of
peri-centriolar material
centrioles
what does PCM contain
gamma tubulin - nucleates the microtubules
give two examples of intermediate filaments
keratin
vimentin
