Cytoskeleton

Question 1

Whats a cytoskeleton?

Answer 1

A network of protein micro filaments and micro tubules that run through the cytoplasm

Question 2

What are microfilaments?

Answer 2

Strands of proteins (actin)that act as tracks for things to move along in the cell

Question 3

What are microtubules?

Answer 3

Hollow protein tubes (like centrioles)

Question 4

Draw a cytoskeleton

Answer 4

physical notes

Question 5

Give features of microfilaments

Answer 5

• known as actin filaments
• made of protein actin
• finer / thinner than microtubules
• give all shape and resist tension
• anchor organelles
• involved in cell movement, contraction and cell shape changes
• play a role in cellular processes like cytokinesis (cell division), cell adhesion and cell signalling

Question 6

What are features of microtubules?

Answer 6

• tube = hollow
• made of protein tubulin
• larger than microfilaments
• similar to centrioles (9+2 arrangement)
• more organelles
• resist compression
• provides structural support to cell
• tracks for intracellular transport
• allows movement of organelles, vesicles and other cellular components
• plays crucial role in cell division by forming the mitotic spindle, which helps segregate chromosomes during mitosis and meiosis

Question 7

What are the functions of cytoskeleton?

Answer 7

• structure support to give (animal) cells their shape
• helps organelles into position
• moves components within the cell eg separating of chromosomes during cell division or exocytosis / cytokinesis (division of cytoplasm)
• maintaining cell shape
• provides structural support
• processes such a cell division, cell movement and intracellular transport

Question 8

What are the three types of fibre in a cytoskeleton ?

Answer 8

• microfilaments
• intermediate filaments
• microtubules

Question 9

What does it mean when you say that the cytoskeleton is a dynamic network?

Answer 9

Moving / Changing

Question 10

State how the cytoskeleton moves organelles around the cell

Answer 10

Using microtubules / tubulin / motor proteins

Question 11

Give the functions of intermediate filaments

Answer 11

• larger diameter than microfilaments but smaller than microtubules
• they are composed of various proteins ie keratins, laminated and vimentin
• they provide mechanical strength, support to cells, anchoring cellular organelles and maintaining cell integrity