Cytoskeleton Flashcards
Cytoskeleton
A network of filaments and tubules throughout the cytoplasm
Roles of Cytoskeleton
1) Provide mechanical support: Help to maintain cell shape
2) Cell motility: Provides cell with movement ability
3) Intracellular Transport: Mediates movement of organelles/molecules
4) Regulates biochemical activity of cell by transmitting mechanical forces
3 Parts of Cytoskeleton
1) Microtubules (thickest)
2) Intermediate filaments
3) Microfilaments (thinnest)
Microtubules
Hollow tubes made of tubulin
Tubulin
Globular protein
–> A protein dimer: Made of two subunits
1) alpha-tubulin
2) beta-tubulin
Microtubules Functions
1) Resisting Compression (protecting from crushing or squishing)
2) Motility
–> The movement of the cell as a whole, organelles/molecules within the cell, and chromosomes (during mitosis)
Centrosome
Where microtubules originate/grow from (by adding on tubulin dimers)
–> Made of 2 centrioles at a 90 degree angle to each other
Centriole
9 sets of 3 (triplet) microtubules arranged in a ring
–> Plants DO NOT have centrioles
Cilia
Occur in large # on the cell (look like little hairs)
–> Beat to move the cell
–> Made of microtubules
Flagella
Occur in small # on the cell (usually 1-3 per cell)
–> Undulate (like a snake) to move the cell
–> Made of microtubules
Structure of Cilia and Flagella
Have a 9 + 2 Structure
–> 9 sets of doublet microtubules arranged in a ring with 2 separate microtubules in the center
Dynein Arms
Molecular motors: Cause the microtubules to move