cytoskeleton Flashcards
1
Q
what are the three families of proteins that make the three types of filament?
A
actin
intermediate
microtubules
2
Q
features of microtubules
A
- The microtubules grow by the addition of α and β tubulin subunits to the positive end of the filament
- the tubulin subunits hydrolyses GTP to GDP
3
Q
features of actin filaments
A
- Actin forms a trackway along which myosin can walk.
- Actin filaments are made up of monomers of the protein actinin
4
Q
features of intermediate filaments
A
- Form a mesh to provide mechanical strength in the cell
- Intermediate filaments are rope-like structures.
5
Q
functions of the cytoskeleton
A
- Allows neurons to extend axons and dendrites
- Drives and guides intracellular traffic of organelles
- Helps change and maintain the shape of the cell.
- Provides a framework for muscle contraction
- Provides mechanical strength to the cell.
- Pulls chromosomes apart at mitosis.
- Splits dividing cells.
- Supports the fragile plasma membrane.
6
Q
what is the structure of actin filament
A
helical polymer
7
Q
what is structure of microtubule
A
hollow tube structure
8
Q
what is structure of intermediate filament
A
rope like structure
9
Q
function of actin filaments?
A
- can form contractile bundles.
- can form gel-like networks.
- can form tight parallel bundles
- actin forms a trackway along which myosin can walk.
10
Q
what do microtubules do
A
form an array in the cell
need a point of nucleation in the cell
11
Q
where do microtubules form from
A
form from the microtubule-organising centre (MTOC).
12
Q
what does the microtubule organising cente mtoc contain
A
a centrosome and mitochondria
