Cell cytoskeleton

What are the functions of the cytoskeleton?

Establishes cell shape, provide mechanical strength, locomotion, chromosome separation in mitosis and meiosis, movement of organelles within a cell

What are the 3 components of the cell cytoskeleton?

Microtubules, microfilaments and intermediate fibres

What is the size and function of microtubules?

25nm in diameter. Globular tubulin proteins polymerise to form tubes. Involved in transport of organelles. Make up the spindle fibres during cell division. 

What is the size and function of microfillaments?

7nm in diameter. Contractile fibres formed from the protein actin. Responsible for cell movement and cell contraction during cytokinesis. 

What is the size and function of intermediate fibres?

8-10nm in diameter. Give mechanical strength to cells and help maintain their integrity.

What are undulipodia and cilia + what are they made up of?

Hair like extensions that stick out from the surface of cells. Made of 9 pairs of microtubules in a circle w/ two more in the middle (9+2 arrangement)

What are the functions of undulipodia and cilia?

Move liquid past the surface of the cell. For single cells this enables them to swim. For anchored cells this moves liquid over the surface of the cell. 

What are flagella made of + where are they present?

Only present in bacterial cells. Made of a spiral of flagellin protein attached by a hook to a protein disc than can rotate. 

What is an advantage of being a eukaryote?

Organelles allow for division of labour. Each organelle is specialised to carry out a specific role.