Extension from the cell which detect
the enviorment around the cell
contain actin filament
Stress fibres
Hold the cell together and keep its
shape as it moves, they stretch and
contract once the cell as extended
Also bundles of actin
Focal Adhesion
Like mini feet, found on the bottom of cells, they elevate
the cell and links the cytoskeleton to the outside
Lamelapodia
Bundling of actin filament together, which
cause the cell to move (treadmilling)
HOW DO CELLS MOVE?
The actin filament subunits line
up parallel at the leading edge,
One end polymerised whilst other
broken down, this is called
treadmilling (lost at -, added on +)
Many F actin do this at the same time
The filament moves forward whilst the actin
filament remains the same size
WHY IS CELL MOTILITY
NEEDED?
Cell Migration
Chemotaxis
Destroying pathogen
Tissue formation
Repair of cells
Cancer
Metastasis
TERMINOLOGY
Leading Edge
Front of the cell
Lagging end
Back of the cell
MITOSIS
Microtubules
The are formed from spindle fibre and they attach to the centrosome
of the chromosone, one from each side on every chromosone. They
pull at the same force and chromosones are pulled apart. They then
depolarise and get shorter moving chromosones to opposite sides of
the cell
At cytokenesis the actin filament strangulate
inbetween the nuclei by becoming shorter (depolarisation)
INTERGRINS
Receptors which connect the
ECM and the cytoskeleton
They bind to matrix molecules causing
them to become activated, they relay
activation into the cytoplasm of the cell