L2 The Cytoskeleton Flashcards
Understand the three main components (their form, function and location) of the cytoskeleton and associated proteins.
The 3 main components of the cytoskeleton are…
- Intermediate filament (IF)
- Microtubules
- Actin
Intermediate filaments are ? than actin filaments in size
larger
Intermediate filaments measure…
10nm in diameter
Cytoskeleton and associated proteins is responsible for the shape and movement of the cel, intracellular transport, position of the organelles. It is a…
Highly dynamic and regulated system
Different cells have different types of Intermediate Filament. These include (7)…
- Keratin
- Desmin
- Neurofilaments (NFL, NFM, NFH)
- Lamins A & B in the nucleus
IF is made up of a bundle of…
8 alpha-helix tetramers
Microtubules measure…
25nm in diameter (the largest of the 3)
Unlike actin, which is built with energy from ATP, microtubules rely on the molecule…
GTP
Microtubules are formed from a globular monomer, called…
Tubulin
Microtubules are present in the cytoplasm, growing out from the centrosome. They are structurally ? but also highly dynamic
Rigid
Name three functions within the cell that rely on microtubules…
Centrosome in interphase, mitotic spindles in a dividing cell & basal body in ciliated cells
Microtubules are assembled from alternating dimers of alpha/ beta tubular. These are arranged to form…
hollow cylinders of 13 protofilaments
Motor proteins associated with microtubules include…
+ Kinesins (moving towards positive end, away from the centre of the cell)
– Dyneins (moving towards the negative end, towards the centre of the cell)
Cilia and flagella are both structured with a…
9 + 2 microtubule arrangement
Microvilli differ structurally from cilia, in that they do not possess a 9 + 2 microtubule arrangement. Instead they consist of…
Actin filaments
