The Cytoskeleton and Microtubules Flashcards
What is the cytoskeleton?
A network of protein fibres that extends throughout the cytoplasm in all eukaryotic cells.
What is the cytoskeleton attached to?
Membrane proteins as well as organelles.
What is the function of the cytoskeleton?
Gives mechanical support to the cell acting as scaffolding to maintain the shape of the cell.
What is the cytoskeleton involved in?
The movement of cellular components such as vesicles or chloroplasts. And is responsible for the movement of whole cells.
What are microtubules the polymers of?
A dimer made from a-tubulin and b-tubulin.
Describe the structure of a-tubulin and b-tubulin
They are soluble globular proteins
What is the diameter of a microtubule.
25 nm
What are the microtubules a component of?
The cytoskeleton
What does the length of the microtubules depend on?
The addition or the removal of tubulin at the ends.
Where do microtubules originate from?
The microtubule organising centre (MTOC)
What does the MTOC contain?
The centrosome
Where is the site of microtubule synthesis in animal cells?
The centrioles within the centrosome
What are spindle fibres made of?
Microtubule
What is disassembled to form the microtubules of the mitotic and meiotic spindles?
Cytoplasmic microtubules
What do microtubules attach to?
Proteins at the centromeres of chromatids.
