Cytoskeleton I+II- Lecture 8/31/21

Question 1

Microtubules structure

Answer 1

Made of tubulin

Question 2

Microfilament structure

Answer 2

Made of actin

Question 3

Intermediate filament structure

Answer 3

lamins, keratin, neurofilaments, vimentin, desman, GFAP

Question 4

Microtubule accessory proteins

Answer 4

MAPS, tau

Question 5

Mictrotubule hyperstable structures

Answer 5

Cilia, flagella, centrioles

Question 6

Microfilament hyperstable structure

Answer 6

Sarcomere, microvilli

Question 7

Intermediate filament hyperstable structure

Answer 7

Desmosomes, hemidesmosomes

Question 8

Microtubule motors

Answer 8

Dynein (retrograde)

Kinesiology (orthograde)

Question 9

Microfilament motor

Answer 9

Myosin

Question 10

Microtubule function

Answer 10

1, Cilia/flagella

2. Mitotic spindles
3. Organelle/cargo transport

Question 11

Microfilament functions

Answer 11

1, phagocytosis,
2, cytokinesis,
3, cell motility
4. Force generation (muscle)
5. Membrane stability (RBC)

Question 12

Intermediate filament functions

Answer 12

Mechanical integrity (nucleus, cell-cell, cell-matrix)

Question 13

Mictrotubule drugs

Answer 13

Taxol, stops microtubules from falling apart once formed
Vinca alkaloids (Stops from forming)

Question 14

Dynein

Answer 14

Microtubule associated motor protein in charge of retrograde (towards nucleus)

Question 15

Kinesin

Answer 15

Designed to bring cargo away from nucleus (orthograde)

Question 16

Lysosome movement

Answer 16

Move on microtubule tracks

Question 17

Centrosomes

Answer 17

Hyperstable microtubule structures that replicate and form centrioles in dividing cells, pull the chromosomes to opposite sides

Question 18

Axonemes

Answer 18

Specialized MT-based structures including the cilia and flagella

Question 19

Basal bodies

Answer 19

Specialized axonemes structure that anchors other axonemes, especially cilia

Question 20

Cilia motion

Answer 20

Whip like motion created by dynein “arms”. There are two arms per 9 doublets.

Question 21

Kartagener’s/Primary Ciliary Dyskinesisa/immobile cilia syndrome

Answer 21

Cilia missing the dynein arms, cannot beat as normal. Leads to situs inversus and infertility

Question 22

Taxol

Answer 22

Binds and stabilizes microtubules, prevents them from falling apart once they grow, cancer drugs

Question 23

Vinca alkaloids

Answer 23

Binds tubulin subunits and prevent them from growing

Question 24

Tau

Answer 24

An accessory protein of tubulin, binds to growing end to stop growth, perfectly regulated, when tau is overexpressed, gets tangled

Question 25

Stress fibers

Answer 25

Actin based structures that provide stability and support for cells, especially endothelial cells

Question 26

B-actin

Answer 26

Often found at the leading edge during cell migration

Question 27

Myosin

Answer 27

Motor molecule that binds with actin to create force in the muscle cells

Question 28

Sarcomere

Answer 28

Hyperstable actin structure in muscle fibers

Question 29

Cytokinesis

Answer 29

The “pinching off” of new cells, actin mediated

Question 30

Platelet aggregation

Answer 30

First step in clotting, is actin dependent

Question 31

Phagocytosis

Answer 31

Actin dependent mechanism

Question 32

Microvilli

Answer 32

Actin filament stabilized structure in intestinal epithelium

Question 33

Listeria

Answer 33

Once ingested by phagosome, rapidly high lacks actin apparatus to to from cell to cell without exposure to other immune cells

Question 34

Actin’s role in erythrocytes

Answer 34

Have to be stable, travel about 300 miles in a lifetime, actin along with Band 3 are used to stabilize these structures

Question 35

Hereditary Spherocytosis

Answer 35

Uncommon genetic diseases caused by defective membrane-cytoskeleton interactions, enlarged spleen, anemia

Question 36

Intermediate filament

Answer 36

Structure like a twisted rope

Question 37

Cell type of lamins

Answer 37

All uncleared cells

Question 38

Cell type of vimentin

Answer 38

Many mesenchyal cells, including endothelial cells and fibroblasts

Question 39

Desmond cell type

Answer 39

Muscle cells. (Smooth, striated, cardiac)

Question 40

Glial fibrillation acidic protein (GFAP) cell type

Answer 40

Glial cells (astrocytes)

Question 41

Neurofilamin cell type

Answer 41

Neurons

Question 42

Keratin cell type

Answer 42

Epithelial cells

Question 43

Desmosomes

Answer 43

Specialized structures that hold two things together that are stabilized by intermediate filaments

Question 44

Blistering diseases

Answer 44

Caused by a defect in the desmosomes, more severe when defect in hemidesmosomes