lecture 6 - cell shape regulation Flashcards
How is the cytoskeleton dynamic?
The components of the cytoskeleton are cosntantly assembling and disassembling to rapidly change the shape of the cell.
What are the three components of the cytoskeleton that provide structure?
Microtubules, Microfilaments, Intermediate filaments
What are microtubules made up of?
Tubulin subunits (dimers) in a twisted helix tube.
What organelle do microtubules sometimes radiate out from?
Centrosomes
What are centrosomes?
An organising centre, that is sometimes surrounded by microtubules, e.g. during the formation of the mitotic spindle
What type cytoskeleton component best resists compression?
microtubules
What structures create cell motility?
Flagella and cilia
What are the cytoplasmic components of flagella and cilia?
Microtubules
What is the role of cilia in a fixed cell?
The cilia beat back and forth, moving fluid/mucous past.
How do the microtubules aid in organelle motility?
ATP powered motor proteins are able to attach to vesicles/other organelles and walk along microtubules to their targets.
What is the structure of microfilaments?
Double chains of actin subunits that twist around each other.
Actin is the component of what cytoplasmic structural component?
Microfilaments
What structures can microfilaments form?
linear strands and 3D networks
What is required to allow microfilaments to branch?
branching proteins
How do microfilaments make the cell rigid?
They form a cortical network which replaces fluid in the cytoplasm, stiffening the cell.