Cytoskeleton Flashcards
Name families of motor proteins on microtubules?
- Kinesins
- Dyneins
- Myosin.
Which end of microtubules do kinesins move towards?
Plus end (cell edge)
Which end of microtubules to dyneins move towards?
Minus end (centrosome).
Which type of motor protein receptors does ER have?
Kinesins.
Which type of motor protein receptor does the Golgi body have?
Dyneins.
Describe the opposite ends of microtubules.
- Polar structures
- Plus end is capable of rapid growth.
- Minus end tends to lose subunits if not stabilised.
Define centromere.
Serves as main microtubule organising centre in animal cells.
What are the main functions of kinesin motor proteins?
- Transport of RNAs and proteins.
- Assembly of cilia/flagella.
- Signalling pathways
- Mitotic spindle formation and chromosome movement
- Organelle movement.
What are the main functions of dynein motor proteins?
- Cytoplasmic dynein
* Ciliary dynein.
Describe the arrangement of cilia and flagella in cilia and flagella.
9 + 2 arrangement (9 make up circle + 2 in centre).
Describe myosin.
- Moves along actin filaments
- Major component of muscle
- Other types present elsewhere.
What are microfilaments me composed of?/ What are the monomers?
•Actin (protein)
May exist as filaments, bundles or networks.
•Tubulin
Where are intermediate filaments found and what is their function?
- Only found in multicellular organisms
- Stabilise cell structure
- Prominent in cells subject to mechanical stress e.g. Epithelial and muscle cells.
Describe the structure of intermediate filaments.
- Unlike tubulin and actin which are globular proteins, these monomers are elongated fibrous molecules.
- Two coiled cool dimers form antiparallel tetrameric subunits (non-polarised).
How many keratins are found in epithelial cells?
Over 20.
