Cytoskeleton Flashcards
What is the cytoskeleton?
A filamentous structure found throughout the cytoplasm
What is the cytoskeleton formed of?
Protein monomers which assemble into repeat structures
What 3 types of filaments are found in the cytoskeleton?
Actin
Microtubules
Intermediate filaments
What is the main property of the cytoskeleton?
It is dynamic - can assemble and disassemble rapidly to suit the cells needs
What is the function of the cytoskeleton?
To provide stability and support to the cell
What can link to the cytoskeleton?
Other cellular components
What are motor proteins?
Proteins that move organelles along filaments and filaments against each other
What is the diameter of an actin filament?
5-9nm
What are actin filaments made of?
Actin = globular protein
- Actin assembles into two stranded helical polymers
What can actin helical polymers form?
3D gels
2D networks
Bundles - by lining up
What are the functions of actin filaments?
Shape
Motility
Where are actin filaments found?
Throughout the body but mainly concentrated beneath the cortex
What is the diameter of a microtubule?
25nm
What are microtubules made of?
Tubulin = globular protein containing alpha and beta subunits
- Long and straight
What structure does tubulin form in microtubules?
Hollow tubes
How do microtubules compare to actin filaments in terms of rigidity?
More rigid
What are microtubules typically attached to?
Centrosomes at one end
What is a centrosome?
A microtubule organising centre
What does the end of the microtubule not attached to the centrosome do?
Grow and shrink
What are the functions of microtubules?
Positioning of organelles
Mitosis
Intracellular transport
What is the diameter of an intermediate filament?
10nm