Cytoskeleton

Question 1

List the actin binding proteins of F-actin

Answer 1

1. thymosin 2. profilin 3.Arp2/3 4. Gelsolin 5.Cofilin 6.Cytochalasins 7.Phalloidin 8.Latrunculins

Question 2

Thymosin role

Answer 2

actin binding protein.

Collects the G-actin in a pool.

Question 3

Profilin’s role

Answer 3

Regulate G-actin binding by ADP/ATP exchanges.

Promotes actin monomer from thymosin to + end of actin filament.

Question 4

Gelsolin’s Role

Answer 4

severes and caps the protofilament preventing the length changes

Question 5

Cofilin role

Answer 5

Stimulates the dissoaciation of ADP-bound G-actin

Question 6

Cytochalasins

Answer 6

bind to the + end forming a cap and preventing further growth

Question 7

Phalloidin

Answer 7

prevents dissociation of protofilament by binding to the G-actin

Question 8

Latrunculins

Answer 8

promotes protofilament dissociation by binding to G-actin

Question 9

Arp2/3

Answer 9

initiates new starting sites for protofilament formation. causes branching.

Question 10

List the types of collagen fiber we need to know.

Answer 10

1. I, general CT and bone, tensile strength
2. II, cartilage, tensile strength
3. III, organ parenchyma, reticular framework
4. IV, basement membrane, scaffolding.

Question 11

Motor proteins and function

Answer 11

1. myosin I, actin and CM, to the +
2. Myosin II, actin and MII, to the +
3. Myosin V, actin and vesicles, both directions
4. kinesins, vesicle/microtubule, to +
5. dyneins, vesicle/microtubule, to -