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Flashcards in Tissue Architecture Deck (54)
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1

Why are cytoskeletons dynamic and adaptable?

Can disassemble, diffuse, and reassemble elsewhere

2

What forms of cytoskeleton filaments are thermally stable?

Multiple protofilaments

 

Single protofilament are not thermally stable

3

What filaments are resistant to stretching forces?

Intermediate filaments

4

What are the main components of cytoskeletal filaments?

Intermediate filaments 

Microtubules

Microfilaments

Associated proteins

5

Mesh-like structure made up of intermediate filaments.

Nuclear lamina

6

Fuctions of intermediate filaments

Form a network throughout the cytoplasm and surround the nucleus

Rope-like properties give high tensile strength

 

Often further stabilized by accessory proteins

–  Cross-link filaments into bundles

–  Link to microtubules, actin filaments, and cell-junctions

7

What intermediate filament is found in epithelial cells?

Keratin filaments

8

What intermediate filament is found in connective tissue cells, muscle cells, and glial cells?

Vimentin and vimentin-related filaments

9

What intermediate filament is found in nerve cells?

Neurofilaments

10

What is the nuclear intermediate filament?

Nuclear lamins

11

Functions of microtubules

Provide tracks for transport vesicles

Mitotic Spindle formation

Cilia and Flagella

12

Binds and stabilizes microtubules

taxol

13

Binds tubulin dimers and prevents polymerization.

Colchicine, colcemid, vinblastine, vincristine

14

What is F actin composed of?

Twisted polymer of G-actin (globular) that has structural polarity

Many must be in association with other proteins to be stable

15

Binds and stabilizes actin filaments

Phalliodin

16

Caps actin filament plus end, preventing polymerization there

Cytochaslin

17

Binds actin monomoers and prevents polymerization

Latrunculin

18

How can actin filaments be modified when bonded to other proteins?

Stabilize

Strengthened

Cross-linked

Organizes

19

What are some extracellular proteins?

Perlecan

Sheet formin collagen (IV)

Fibrillar collagen (I,II,III)

Lamninin

Fibronectin

Nidogen/entactin

20

Main structural protein in ECM/connective tissue and basal laminae.

Collagen

21

How do collagen types differ?

28 types

Homotrimers

Heterotrimers

Form collagenous triple helix

Can be fibers, sheets, or transmembrane structures

22

Where is the precollagen prepared for secretion

Secretory Vesicles 

 

23

Scurvy is caused by loss of what cofactors

Ascorbate or Iron

24

Disease caused by defects in collagen or enzymes contributing to synthesis.

Ehlers-Danlos Syndrom

Weakens connective tissue in the skin, bones, blood vessels, and organs

25

Links cells to extracellular matrix, or basil lamina

Focal Contacts

26

What are the four classes of Cell Adhesion Molecules

Cadherins (e-cadherins)

Ig-superfamily CAMs (NCAM)

Integrins (avB3)

Selectins (P-selectins

27

What are the common aspects of cadherins?

Ca2+ dependent adhesion molecule – Important in formation of junctions between cells (epithelial “sheets”) such as desmosomes and adherens junctions

–  Homophilic interactions (extracelluar)

–  Interact with cytoskeleton (actin)

28

What are classic cadherins?

Cytoplasmic domain interacts with beta-catenin, alpha-catenin, and p120

Linked to the actin cytoskeleton

Associated with adherens junctions

29

What are the classic cadherin examples listed?

E-cadherin (epitheilial)

VE-cadherin- (vascular-endothial)

N-cadherin- (neural)

 

30

What are atypical cadherins?

Function without interaction with catenins or a link to the actin cytoskeleton.