Cytoskeleton

Question 1

What is the purpose of the cytoskeleton

Answer 1

• cell movement
• cell shape
• delivery of cargo
• intracellular location of organelles

Question 2

three types of cytoskeletal proteins

Answer 2

• intermediate filaments
• actin filaments
• microtubules

Question 3

form a network throughout the cell, nuclear lamina, high tensile strength

Answer 3

intermediate filaments

Question 4

intermediate filaments are assembled similarly to a

Answer 4

twisted rope

Question 5

assembly of intermediate filaments

Answer 5

• alpha helical rod of monomer
• coil-coil dimer
• staggered tetramer of two coiled dimers
• two tetrameters packed together
• 8 tetrameres — filament

Question 6

2 main classes of intermediate filaments

Answer 6

• cytoplasmic

- nuclear

Question 7

3 types of cytoplasmic intermediate filaments

Answer 7

• keratin filaments
• vimentin
• neurofilaments

Question 8

IF found in epithelial cells

Answer 8

keratin filaments

Question 9

IF found in CT cells, muscle cells, and glial cells

Answer 9

vimentin

Question 10

IF found in nerve cells

Answer 10

neurofilaments

Question 11

class of intermediate filaments under nuclear intermediate filaments

Answer 11

nuclear lamina (in all animal cells)

Question 12

What is the disease associated with keratin?

Answer 12

epidermolysis bullosa simplex

(do not form keratin filaments in the skin, skin has mechanical stress blisters)

mutation in keratin 5 and keratin 14

Question 13

What disease is associated with the nuclear laminin?

Answer 13

progeria

Question 14

• long hollow tubes
• can rapidly assemble and disassemble
• form basis of mitotic spindle, cilia, and flagella

Answer 14

microtubules

Question 15

what are the organized centers that microtubules form

Answer 15

• centrosomes
• mitotic spindle poles
• basal body of cilia

Question 16

form of a microtubule

Answer 16

alpha and beta tubules that make a protofilament, 13 protofilaments

Question 17

+ part of tubulin

Answer 17

beta, away from body cell

Question 18

• part of tubulin

Answer 18

alpha, towards cell body

Question 19

when microtubules switch back and forth between polymerization and depolymerization

Answer 19

dynamic instability

Question 20

a type of drug that can affect microtubules, will bind and stabilize microtubules (gain more tubular, more growth)

Answer 20

taxol

Question 21

a type of drug that can affect microtubules, binds tubular dimers and prevents polymerizations (loose tubulin proteins)

Answer 21

colchicine, colcemid, vinblastine, cincristine

Question 22

guide the transport of organelles, vesicles, and macromolecules

Answer 22

microtubules

Question 23

motor proteins that move along cytoplasmic microtubules belong to two families:

Answer 23

• Kinesin

- Dyneins

Question 24

generally move towards the plus end of microtubule (outward from the cell body)

Answer 24

kinesin

Question 25

move toward the minus end (toward cell bod)

Answer 25

dyneins

Question 26

use ATP to walk down microtubules

Answer 26

kinesins

Question 27

longer, wave like motion

Answer 27

flagella

Question 28

small hair like projections, whip like motion

Answer 28

ciliar\

Question 29

essential for cell movement

Answer 29

actin

Question 30

how are microtubules arrange in flagella and cilia

Answer 30

9+2

Question 31

actin bound with ATP

Answer 31

polymerizes

Question 32

actin bound with ADP

Answer 32

loose and depolymerizes

Question 33

actin needs ---- while microtubules need ---

Answer 33

ATP, GTP

Question 34

bind actin monomers to prevent them from being added to filaments

Answer 34

thymosin and profilin

Question 35

promote filament formation, actin-related biding proteins

Answer 35

formins and ARP's

Question 36

cell crawling depends on

Answer 36

actin

Question 37

3 steps of cell crawling:

Answer 37

1. cell pushes out protrusion at the front (leading edge) 2. the protrusions adhere to the surface 3. the rest of the cell drags itself forward as a result of anchorage points

Question 38

two filaments at the leading edge that allows movement

Answer 38

lamelipodium, filopodium

Question 39

sheet like

Answer 39

lamelipodium

Question 40

finger like projection

Answer 40

filopodium

Question 41

actin arrangement is regulated by the

Answer 41

Rho family of GTPases

Question 42

muscle contraction is dependent of the interaction of

Answer 42

myosin and actin