Lecture 4: Cytoskeleton I Flashcards
Cytoskeletons support cell _ and _
shape, movement
Name the three types of cytoskeletons
actin, tubulin, and intermediate filament
Describe where actin is located in a cell
actin is located inside the perimeter of the cell
Describe where intermediate filament is located in a cell
IF is on the inside randomly squiggling around the entire cell
Describe the location of tubulin in a cell
tubulin is inside of the cell stretching across the cell like spider legs
Filamentous actin is made up of __ subunits
G-actin
G-actin (monomeric building block) assembles into __
F-actin
F-actin assembly depends on ___
ATP hydrolysis (energy required)
Nucleation
monomers slowly form stable complexes
Elongation
rapid elongation of filament by addition of subunits to both ends
Steady State
subunits added and removed at similar rates at each end
Actin filament is ___
asymmetric (plus and minus ends look different)
Subunit addition occurs more rapidly/easily on which end?
plus
What is treadmilling?
the removal of actin monomers from the pointed ends of filaments and their reincorporation at the barbed end
Why is treadmilling important?
It is essential for cell motility
