Organisation within cells: The Cytoskeleton

Question 1

what are the functions of the cytoskeleton?

Answer 1

support
movement
resistance to mechanical forces

Question 2

What three distinct types of filaments is the cytoskeleton made up of?

Answer 2

microfilaments
intermediate filaments
microtubules

Question 3

the cytoskeleton is…

Answer 3

dynamic

Question 4

function of the cytoskeletal element: microfilaments

Answer 4

cell shape and motility

Question 5

characteristics of the cytoskeletal element: microfilaments?

Answer 5

actin
5-9nm
made of the globular protein actin which assembles into two stranded helical polymers

Question 6

location of the cytoskeletal element: microfilaments?

Answer 6

dispersed through the cell but concentrated beneath the cortex

Question 7

Characteristics of the cytoskeletal element: intermediate filaments?

Answer 7

10nm diameter
Various intermediate filament proteins which are themselves filamentous
Extended a helical regions wind together into dimers, which then associate into tetramers that wind together to form rope likle fibres

Question 8

tetramers?

Answer 8

soluble subunit

Question 9

functions of intermediate filaments?

Answer 9

mechanical support of cell structures
less dynamic than microfilaments and microtubules

Question 10

Examples of intermediate filaments:

Answer 10

lamins
keratins
vimentin
desmin (slide 8)

Question 11

9

Question 12

function of microtubules?

Answer 12

positioning organelles
intracellular transport

Question 13

needs to process premRNA before it leaves nucleus by using the capping of GTP???

Question 14

actin filaments?

Answer 14

polymer of actin monomers

Question 15

diameter of actin filaments?

Answer 15

7nm in diameter

Question 16

gap junctions?

Answer 16

allow sodium ions to go through and carry the signal so they myocytes can contract together