2.1.1 J) Importance of the Cytoskeleton

Question 1

What is the cytoskeleton?

Answer 1

• the structure that maintains the shape and internal organisation of the cell
• network of protein threads running through cytoplasm

Question 2

Cytoskeleton importance + function:

Answer 2

• provides mechanical strength to cells helping to strengthen the cell and maintains its shape
• aids transport of organelles and materials within cells enabling cell movements
• microtubules and microfilaments support the cell’s organelles keeping them in position

Question 3

What is the cytoskeleton made up of?

Answer 3

Network of proteins consisting of:

• Microtubules (made of tubulin, very thin protein strands)
• Microfilaments (tuny protein cylinders)- intermediate filaments, actin microfilaments

Question 4

What do cytoskeletal motor proteins do?

Answer 4

• Cytoskeletal motor proteins (myosin, kinesins and dyneins) act as molecular motors
• They hydrolyse ATP as an energy source.

Question 5

How does the cytoskeleton provide mechanical strength?

Answer 5

• Push against the membrane to provide mechanical strength and keep the shape stable
• Intermediate filaments also anchor certain organelles (e.g. nucleus) in position
• They also can extend between tissues, allowing cells to adhere to one another and allow cell signalling

Question 6

How does the cytoskeleton allow transport within cells?

Answer 6

• Microtubules form the track over which motor proteins ‘walk’ and drag organelles
• Microtubules also make up the spindle fibres which pull chromosomes to the poles.

Question 7

How does the cytoskeleton allow cell movement?

Answer 7

Microtubules make up the cilia and undulipodia which enable cell movement

Question 8

Diagram of cytoskeleton:

Answer 8