module 2 - 2.5 continued - cytoskeleton of eukaryotic cells

Question 1

what is the function of the cytoskeletion in eukaryotic cells?

Answer 1

• maintains shape and stability of the cell (unlike surface membrane, no mechanical strength)
• holds organelles in place
• controls cell and organelle movement

Question 2

what components make up the cytoskeletion in eukaryotic cells?

Answer 2

cytoskeleton made of 3 components:
- microfilaments (actin filaments)
- microtubules
- intermediate fibres

Question 3

what are microfilaments?

Answer 3

• solid and smaller than microtubules
• composed of actin (protein)
• acts as skeleton, helping support the cell
• responsible for cell movements

Question 4

what are microtubules?

Answer 4

• composed of globular tubulin proteins
• acts as ‘roads’ for vesicles and organelles
• some organise into 9+2 configuration
• self-assemble to form hollow tublin subunits to form cilia, flagella and spindle fibres

Question 5

what are intermediate fibres?

Answer 5

• intermediate diameter between microtubules and microfilaments
• add mechanical strength to maintain integrity of the cytoskeleton

Question 6

what is mucous?

Answer 6

• a slippery aqueous secretion produced by, and covering, mucous membranes/ glands
• contains inorganic salts, antimicrobial enzymes, immunoglobulins and glycoproteins
• protects epithelial cells in the linings of digestive, respiratory and urogenital systems