Chapter 11: Cell Interactions

Question 1

Extra cellular layer in Eukaryotes consist of _____

Answer 1

Fiber composites

Question 2

Fiber composites: ____-______ network of ____ _________ embedded in a stiff surrounding called the ____ ________

Answer 2

cross-linked
long filaments
ground substance

Question 3

The fibers resists _______.
Stiff ground substance resist _________.

Answer 3

tension

compression

Question 4

Describe the Primary cell walls of plants

Answer 4

Primary cell walls:
-when plant cells form, they secrete a fiber composites called a primary cell wall
-composed of long stands of cellulose bundled into microfibrils that form a crisscrossed network.
-netwok is filled w/hydrophilic gelatinuous polysachharides called pectin that keep cell wall moist.
-primary cell wall helps shape a plant cell; counteracts turgor pressure.

Question 5

Describe Secondary Cell Walls of Plants

Answer 5

-as plant cells mature and stop growing, some secrete a secondary cell wall inside primary cell wall
-in cells that form wood, secondary cell wall contains lignin

Question 6

key words: collagen, integrins, laminins, fibronectins, metastasis

Describe the extracellular matrix produced by animal cells.

Answer 6

-provides structural support
-has a ground substance of gelatinous polysaccharides and network of protein fibers: glycoproteins called collagen
-collagen/other ECM proteins are more elastic and bendable than cellulose
-integrins bind to extracellular cross-linking proteins
-laminins bind to toher ECM components such as fibronectins that bind to collagen
-breakdown leads to metastasis

Question 7

Describe how adjacent cells attach to and interact with one another.