16) Unit 1 - The Cyctoskeleton

Question 1

what is the cytoskeleton

Answer 1

• a network of proteins extending throughout the cytoplasm.
• found exclusively in eukaryotes
• dynamic so continuously breaking down and reforming

Question 2

what is the skeleton attached to

Answer 2

the cell membrane by using proteins in the cell membrane, which are then attached to the extracellular matrix

Question 3

describe 4 roles of the cytoskelaton

Answer 3

• provide mechanical support allowing the cell to maintain its shape
• provide anchorage for many organelles so they stay in the same area
• allow movement of cell organelles
• allow movement of the whole cell

Question 4

what is the role of the cytoskelaton in cell division

Answer 4

• responsible for the movement of chromosomes during the process of meiosis or mitosis
• responsible for the division of the cytoplasm in the animal cells

Question 5

list 3 components of the cytoskelaton

Answer 5

• micro filaments
• intermediate filaments
• microtubles

Question 6

describe microtubules

Answer 6

• hollow cylinders
• dimers of tublin (aplha and beta tublin)
• dynamic - continuously assembling and disassembling

Question 7

what is the role of microtubles

Answer 7

•control the location and movement of organelles and other components e.g. enzymes - this is possible as they are dynamic

Question 8

where does microtubles come from?

Answer 8

•originate from centrosome in animal cells.

Question 9

what is the role of microtubles in chromosome formation

Answer 9

during cell division microtubles form spindle fibres

the spindle fibres attach to the centromere of chromosomes

spindle fibres shorten due to the dynamic microtubles, and separate chromosomes to opposite poles of the cell