Structure - Cytoskeleton Flashcards
What are the functonal processes of the cytoskeleton?
Endocytosis
Cell Divsion
Intra-cellular Transport
Motility
Force transmission
External force reaction
Adhesion
What three filaments regulate cytoskeletal processes?
Actin Filaments
Microtubles
Intermediate Filaments
What is the structure of Actin?
G-actin monomers forming F-actin, helical sturctures, with two charged ends(+ is where polymerisation occurs and contains more ATP)
What is actin filaments involved in?
Shape generation, movement and focal adhesion
What are myosin and actin responsible for in tandem?
Anti-parallel actin contraction coupled with ATP hyrdolysis
How does Myosin II generate contractions?
Pulling on anti-parallel actin filaments, activated by Regulatory Light Chain
What is an example of Actin in motility?
Acrosome reaction in echinoderm sperm, forming protrusion when sperm detects egg for penetration
How does the cytoskeleton influence the shape of EC?
EC require different protein compositions, allowed by tight cell junctions
What is the function of EC?
Transport nutritional molecules across intensitne walls to the vessels
What are examples of diversity of CS function?
Macrophage engulfment
EC Compositional differences
Microfilaments
These are actin polymerised organised into bundles, structuring the PM, microvill, serve as tracks for myosin, about 7nm in diameter
Microtubules
Formed by tubulin, locomoting organelles, supporting flagella/cilia, cargo transport, 8-10nm in diam
Intermediate Filaments
These support membrane and provide structure/integrity to cells and tissues, being 25nm
What structures can microfilaments form?
Bundle(microvilla), less ordered belwo the PM, cell cortex, supporting it
Adhesion Belt
This is a continous band-like sturcture between adjacent cells