cytoskeleton Flashcards
functions of the cytoskeleton
- determines cell shape and polarity
- causes tension and locomotion
- organize and drive intracellular traffic
- basis for mitosis and meiosis
three major fibers that make up the cytoskeleton
- microfilament (actin)
- intermediate filament
- microtubules
-common characteristics to all fibers
- self-assemble
- hyperstable structures: cilia and flagella, f-actin in sarcomere, actin bundle in instestine, intermediate filament in desmosomes
- all thre are organized around specific structures
- highly regulated
- equilibrium can be disrupted with drugs
basic characteristics of microtubules
largest of the three fibers
organeller transport
- carried out by microtubules wihch act as the tracks
- bring synaptic vesicles to and from the synapse
dynein and kinesin
dynein functions in retrograde transport, toward the cell body (endocytosis, away from synapse)
-kinesins function in orthograde transport toward the cell surface (exocytosis, towards synapse)
MT and cell motility
MT makes up cilia and flagella
MT and cell division
MT make up the basis of the cell’s centromeres that become spindle fibers during mitosis
polarity of MTs
grow in a negative to positive direction
axoneme
- makes up the core of cilia and flagella
- contains dynein arms
centrioles
present as pairs in the centrosomes
-take part in mitosis by creating the mitotic spindle
basal bodies
name given to centrioles that nucleate MTs in the axoneme
-function in anchoring cilia and flagella to the cell
centrosome
pair of centrioles surrounded by pericentriolar material that contains the unique tubulin isoform, gama-tubulin
-gama tubulin nucleates MT assembly