18-Cytoskeleton Flashcards
What is the cytoskeleton?
An intricate network of protein filaments that extends throughout the cytoplasm
What is the role of the cytoskelteton?
Strength and support to cell Allows cell shape changes Cell movement Cell contraction Wound healing Cell division Interaction with other cells Organisation of cell interior
Name the three types cytoskeletal filaments
Intermediate filaments
Microtubules
Actin filaments
What is the role of intermediate filaments?
Form a network of fibres inside that provide tensile strength
IFs allow cells to resist external forces such as stretching
What are the three main proteins of Intermediate filamets?
Keratin, vimentin and lamins
How do intermediate filaments provide a strong cytoskeleton?
the network of IFs desmosomal junctions become tensed and limit stretching in response to external forces.
What are the two different types of intermediate filaments?
Cytoplasmic and nuclaer
What are microtubules?
Stiff, hollow tubes made of the protein tubulin
Define microtubule expansion
Microtubules extend from an organising centre such as a centrosome, a spindle pole or the basal body of a cilium
Define microtubule contraction
If the growing microtubule doesn’t attach to something in the cell it will shrink
What is the centrosome?
Lies near the nucleus and has y-tubulin rings and each ring serves as the starting site for growth of a microtubule
What is the microutubules connection to the centromere?
MT are anchored at the centrosome close to the nucleus
What is dynamic instability?
Microtubules anchored in the centrosome can grow and shrink independently of each other
How is dynamic instability regulated?
Regulated by g-proteins
What are actin filaments?
AT are fibres involved in cell movement and shape
