8. Tissue Architecture Flashcards
Why might intermediate cytoskeletal filaments be resistant to stretching forces?
Because lateral contacts dominate in the organization of fibers, preventing stretching.
For intermediate filaments:
What do they do?
Where are they found?
Where are they anchored?
Enable cells to withstand mechanical stress (Great tensile strength)
Cytoplasm of most cells
Anchored to the plasma membrane at cell - cell junctions.
What configuration of protiens do you find in an intermediate filament?
8 staggered tetrameres form a region, which staggers to another 8 staggered tetrameric region in the growing strand.
In what disease might you find mutations affecting the basal lamina?
Progeria
What three structures do intermediate filaments make up in the cytoplasm of cells?
Keratin filaments
Vimentin (and vimentin-related) filaments
Neurofilaments
What role do intermediate filaments play in the nucleus?
They form the nuclear lamina
What roles to microtubules play in the cell?
They are vital to organization.
They form the mitotic spindle for chromosome segregation
They are part of cilia and flagella
On what end of a microtubule do you find gamma-tubulin?
The minus end
On which end of a microtubule might you see faster growth?
The plus end
What configuration of protiens makes up a microtubule?
Rings of alpha and beta tubulin stacked on top of each other.
What serves as the branching off point for microtubules at the centrosome?
Small rings of gamma-tubulin on the outside of the centrosome matrix
What stablizes microtubules at the distal end?
Microtubule capping protien
What does Taxol do?
Binds and stabilizes microtubules
Microtubules are like taxis for dynein. Taxol keeps those taxis going.
What four drugs mentioned in the slides bind tubulin dimers and prevent their polymerization?
Colchicine / Colcemid
Vinblastine / Vincristine
- Tubulin would like to get a job as a microtubule, but it can’t because of its CV*
- BLAST! CHRIST! I can’t get a job!*
For Microfilaments:
What are they made of?
What can help them become stable?
What do they do?
Fibrous F-Actin is made of a twisted polymer of G-Actin (globular actin)
They are often unstable unless associated with other protiens
They are associated with cell movements (locomotion, phagocytosis, cell division, contraction, etc)