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Flashcards in cytoskeletal system Deck (16)
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1

Prokayote similarities of MT, MF, IF

MT-FtsZ

MF- MreB

IF- Crescentin

2

Structure of MT

Hollow tube with a wall consisting of 13 protofilaments

3

MT assembly steps

1. tubular dimmers combine into oligomers (nucleation)

2. oligomers form linear chains of protofilaments

3. protofilaments make sheets, sheets with 13 close into tube

4. elongation via addition of tubular heterodimers

4

The GTP bound to the b subunit is hydrolyzed to GDP after the heterodimer is added to the MT T/F

T

5

Antimitotic drugs

disrupts mitotic spindle of dividing cells

6

effects of colchicine and taxol on MT assembly

C- binds to the GTP binding domain

Taxol- binds to MT and stabilizes then, arrests dividing cells in mitosis

7

roles of MF

-contractile fibres in muscle cells
-cell movements
-developing and maintaining cell shape (cell cortex, microvilli)

8

2 groups of actin

1. muscle specific (a)
2. non muscle actins (b+y)

9

MF assembly

monomers of g actin add on plus side of F actin MF

10

3 drugs that affect polymerization of MF

Cytochalasins- prevents addition of new monomers

Latrunculin A- sequestering actin monomers

Phalloidin- stabilizes MFs

11

What does Arp2/3 do

WASP activates arp2/3 complex and nucleation on the sides of filaments occur

12

How does listeria infect organisms

attaches to host after binding to E cadherin
Spreads to nearby cells by producing a comet tail of polymerized actin

13

Function of IF

structural or tension bearing (most stable but dynamic)

14

T/F IF subunit proteins are tissue specific

T

15

IF assembly

dimers align laterally to form tetramer
Tetramer aligns to form protofilaments
fully assembled IF is 8 protofilaments thick

16

IF disease

Epidermolysis bulls simplex (keratin mutation)