Chapter 10 - Cytoskeleton Flashcards
1
Q
Three cytoskeleton components
A
- Intermediate Filaments
- Microfilaments
- Microtubules
2
Q
Four cytoskeleton functions
A
- Cell shape
- Cell division
- Cell mobility
- Organelle movements
3
Q
Microfilaments
A
- smallest
1. Protein Component: Actin
2. Structure: Two intertwined filaments
3. Function: -Microvilli
- Cytoplasmic contractile bundles
- Pseudopods/cell shape
- Cell devision contractile ring
4
Q
Intermediate Filaments
A
- Protein Components: Depends on cell type, ex: skin contains keratin
- Structure: Proteins assemble into supercoiled, rope-like filament cables
- Function: -Provides cell strength
- Anchoring of cellular components
- Cell adhesion
* EBS: mutation involving keratin that results in blistered skin
5
Q
Microtubules
A
- only in eukaryotes
- important in cell division
1. Protein Components: alpha and beta tubulin & tubulin dimer
2. Structure: Hollow tubes made of 13 tubulin filaments originating from microtubule organizing centre (centrosome)
3. Function: -cell shape and organelle movements
- movement of chromosomes during cell div.
- cell mobility
6
Q
Microtubule Organization Centre (Centrosome) *diagram required
A
- rings of gama-tubulin are the anchor point for microtubule biosynthesis
- There is no cap protein-> they will grow until they break down
- Plus end is the growing end and the minus end is anchored
7
Q
Motor Proteins
A
- Movement of organelles, macromolecules, contraction and amoeboid movement of cells depends on motor proteins
- Use ATP to stimulate “walking” of motor proteins along the cytoskeleton
- Kinesis and dynein walk along microtubules
- Myosis walk along microfilaments
8
Q
Mechanism of Kinesin Movement (1 step)
A
- the “feet” bind ATP and that controls their ability to interact with the microtubules
- the hydrolysis of ATP causes a conformational change in the foot; it swings and binds again to move down the m.t.
- they walk one micrometer/second.
