Cytoskeleton Flashcards
The inside of a cells is basically an _________ ________ _________
organized super highway
Give a brief history of cytoskeleton discovery (2 dates)
1903: Nikolai Kolstov first described cytoskeleton as a network of tubules that control shape
1931: Paul Wintrebert coined cytoskeleton
What are the 3 main types of cytoskeletons?
Microfilaments (actin)
Intermediate filaments
Microtubules
Describe the shape of the 3 types of cytoskeletons
Microfilaments: 2 strands intertwined
Intermediate filaments: Like a strong rope (many strands intertwined)
Microtubules: Hollow cylinder
What are microfilaments made of?
Linear polymers of G-actin
What are microfilaments used for?
- Generate force when the growing end bashes against the membrane
- Act as a scaffold for myosin motor proteins to walk along
- muscle contraction, cell movement, intracellular transport, maintenance of eukaryotic cell shape, cytokinesis (cell division), cytoplasmic streaming.
What are intermediate filaments made of?
Tetramers of red-like proteins that are tightly bundled into long ropelike filaments
What are intermediate filaments used for?
- Provide internal scaffold to help anchor organelles and the nucleus and organize 3D structure of cell
- Maintain overall cell shape and form part of the cell-cell connections that allow cells to communicate with each other
What are mutations intermediate filaments linked to?
Premature again and muscular dystrophy
What are microtubules made of?
Hollow cylinders composed of tubulin protein monomers
How do microtubules grow?
They grow at the positive and and shrink at the negative end
What are microtubules used for?
They form part of motile structures such as cilia and flagella
Crucial for cell division
Transport organelles along their length
How did scientists discover the functions of the cytoskeleton?
Direct observations of the cytoskeleton
Effects of mutations in cytoskeleton structure or function
How the cytoskeleton responded to various conditions
What are the 3 main function of the cytoskeleton?
- Structural support
- Motility
- Regulate biochemical activities
What makes the cytoskeleton good for maintaining cell shape?
Quick to dismantle and reassemble in another part of the cell
How do nutrient absorbing epithelial cells in the small intestine use cytoskeletons?
They use microfilaments to form microvilli, which increases the surface area of the cells