Cytoskeleton Flashcards
Cytoskeleton in prokaryotes
structural proteins that maintain the shape
- also have proteins that form a constricting band around the cell when dividing
how can cells be organised by cytoskeleton protein molecules
Polymerisation
What are cytoskeletons made of
Microtubules/Microfilaments/intermediate filaments
What are microtubules formed from
polymerisation of tubular monomers
what do microtubules provide
rigid intracellular Skelton
how many subunits in a microtubule cross section
13
Characteristics of microtubule
- polar
- positive end capable of rapid growth
- negative loses subunits if not stabilised
- stabilised by embedding in centrosome
- centrosome lies next to nucleus
Centrosomes
main MTOC
centrioles have 9 triplet microtubule assembly
What protein in responsible for microtubule nucleation and anchoring
PCM
What effect does Colchicine have on microtubules
bind to a single tubular molecule and prevents polymerisation
- prevents spindle formation and cell division
What drug has the opposite effect to Colchicine
Taxol
What are motor proteins
use the microtubule network as scaffold to position organelles
What are the two families of motor proteins on microtubules
kinesins (move towards plus end)
- cell edge
Dyneins (moves towards minus end)
- centrosome
Cilia vs Flagella
flagella longer and cells tend to have very few
cilia shorter and present in numbers, more complicated locomotion
How are microtubules arranged in cilia and flagella
9 pairs