5. Cytoskeleton

Question 1

What type filament is hollow while the other two are solid?

Answer 1

Microtubules

Question 2

What type filament is made of different proteins depending on the cell type while the others always have the same from cell to cell?

Answer 2

intermediate

Question 3

Put the 3 main types of fibers from smallest to biggest.

Answer 3

microfilaments–>intermediate–>microtubules

Question 4

Where do actin microfilaments tend to be localized?

Answer 4

at the periphery of the cell. (Cell Cortex)

Question 5

what provides support for the lipid bilayer of cell surface membrane (scaffolding)?

Answer 5

microfilaments (actin)

Question 6

What is the backbone of certain types of cell processes like microvilli, terminal web?

Answer 6

microfilaments (actin)

Question 7

What gives stabilization of integral membrane proteins (receptors) and subsequent focal adhesion site?

Answer 7

microfilaments (actin)

Question 8

Each microvilli has internal actin microfilaments which then extends down and integrates into the _________.

Answer 8

terminal web

Question 9

The terminal web integrates into _______.

Answer 9

zonula adherens

Question 10

What interconnects each epithelial and integrates them into a continuous sheet, which gives the sheet and rooted microvilli more strength and support?

Answer 10

zonula adherens

Question 11

what are the 4 players involved in anatomy of an attachment site for microfilaments.

Answer 11

1. extracellular substrate for cell attachment
2. Integrins
3. Actin Binding protein
4. Actin

Question 12

___________: adhesion to ECM via integrin; stabilize cell morphology (can be permanent - epith to basal lamina - or transient - cell mvmnt)

Answer 12

Focal adhesion site

Question 13

transmembrane protein bound to cytoskeleton on intracellular side & to the ECM on outside

Answer 13

integrin

Question 14

_______: pharmacological; depolymerizes F-actin to G-actin

Answer 14

Cytochalasin B

Question 15

______ & _______ bind to G actin and inhibit polymerization. They are also important for cell movement.

Answer 15

Profilin & thymosin

Question 16

What connects integrin w/ F-actin?

Answer 16

Actin Binding Protein

Question 17

AA sequence that connects w/ integrin and is found in collagen, fibronectin, & laminin

Answer 17

RGD = arginine glycine asparagine

Question 18

What is the addition & removal of actin molecules to a fiber at the same rate?

Answer 18

Treadmilling

Question 19

__ actin is a monomer

Answer 19

G

Question 20

__ actin is organized into fibers

Answer 20

F

Question 21

How do you regulate the length of a filament?

Answer 21

capping proteins

Question 22

What use myosin motors to move fibers?

Answer 22

Contractile bundles

Question 23

What bundles are used for organization and structure?

Answer 23

Parallel Bundles

Question 24

Contractile have what type of polarity?

Answer 24

opposite polarity

Question 25

Parallel bundles have what type of polarity?

Answer 25

same polarity

Question 26

What fiber is made of tubulin and radiates from the center of the cell?

Answer 26

Microtubules

Question 27

Microtubules are made of polymerized _______ dimers with alpha and beta subunits.

Answer 27

Tubulin

Question 28

The #___ alpha and beta subunits form each of the ___________.

Answer 28

13 | protofibril ring

Question 29

Microtubules are in _____________with the available subunit pool.

Answer 29

dynamic equilibrium

Question 30

_______ is the "motor" that moves toward the plus end which is at the periphery of the cell.

Answer 30

Kinesin "kicks things out of the cell"

Question 31

________ deliver the vesicle to the periphery where the actin microfilaments are located.

Answer 31

microtubules

Question 32

_____ can move vesicles on MTs which are then moved by ____ on MFs.

Answer 32

- MAP (microtubule associated proteins) | - myosin

Question 33

_______ is the "motor" that moves toward minus end.

Answer 33

dynein

Question 34

What is the mitotic apparatus made up of?

Answer 34

microtubules

Question 35

Microtubules are ____ in size while microfilaments are _____.

Answer 35

- 25nm | - 7-10nm

Question 36

Colchichine destabilizes _________

Answer 36

Microtubules

Question 37

Cytochalasin B destabilizes ________

Answer 37

microfilaments

Question 38

______ move by MT's sliding past one another.

Answer 38

cilia

Question 39

Stucturally the base of the axoneme has a __________ which has a 9+0 arrangement of triplet microtubules.

Answer 39

basal body (similar to a centriole)

Question 40

Fibers that integrate into the nuclear membrane both giving it support and helping to position the nucleus in the cell giving a "nuclear ghost" during staining.

Answer 40

Intermediate filaments

Question 41

______ are resistant to most enzymes and are extremely stable.

Answer 41

intermediate filaments

Question 42

What do intermediate filiaments bind to?

Answer 42

- Terminal web - Each other (microtrabecular lattice) - desmosomes - nuclear pore complexes

Question 43

Cytokeratin- Filament type? Cell Type?

Answer 43

- Tonofilament | - Epithelial

Question 44

Vimentin- Filament type? Cell Type?

Answer 44

- intermediate filament | - fibroblast/smooth muscle

Question 45

Desmin- Filament type? Cell Type?

Answer 45

- intermediate filament | - musle

Question 46

GFAP (glial fibrillary acidic protein)- Filament type? Cell Type?

Answer 46

- Glial | - Astrocyte

Question 47

Lamins are present in what cell type?

Answer 47

all cell types