Chapter 16

Question 1

consist of a glycine in every 3rd position

Answer 1

Triple helix domains

Question 2

Proline is frequently found in the __ position and hydroxyproline in the __ position.

Answer 2

X, Y

Question 3

________ are thought to stabilize the triple helix by forming hydrogen bonds

Answer 3

Hydroxyl groups

Question 4

the only GAG that is a single long polysaccharide chain

Answer 4

Hyaluronan

Question 5

GAGS linked to proteins

Answer 5

proteoglycans

Question 6

A distinct site of on fibronectin is recognized by

Answer 6

integrin

Question 7

Integrins bind: (3 examples)

Answer 7

collagen, fibronectin, and laminin.

Question 8

Fibronectin has binding sites for:

Answer 8

collagen and GAGs

Question 9

Basal laminae are mostly type ___ collagen

Answer 9

IV

Question 10

four groups of cell adhesion molecules

Answer 10

Selectins
Integrins
Immunoglobulin (Ig)
Cadherins

Question 11

mediate transient interactions between leukocytes and endothelial cells or blood platelets.

Answer 11

selectins

Question 12

An adhesion molecule on one cell recognizes a different molecule on another cell.

Answer 12

heterophilic interaction

Question 13

adhesion molecule on one cell binds to the same molecule on another cell.

Answer 13

Homophilic interaction

Question 14

mediate homophilic interactions.

Answer 14

cadherins

Question 15

form a seal that prevents free passage of molecules and ions between cells.

Answer 15

tight junctions

Question 16

Tight junctions provide minimal adhesive strength between the cells, so they are usually associated with adherens junctions and desmosomes in a:

Answer 16

junctional complex.

Question 17

open channels through the plasma membrane.

Answer 17

gap junctions

Question 18

Gap junctions also allow passage of signaling molecules, such as:

Answer 18

cAMP and Ca2+

Question 19

Gap junctions consist of trans-membrane proteins in the _______ family

Answer 19

connexin

Question 20

Six connexins form a

Answer 20

connexon

Question 21

Specialized gap junctions occur on specific nerve cells and form an

Answer 21

electrical synapse.

Question 22

acts as a glue to hold adjacent cells together

Answer 22

middle lamella

Question 23

Adjacent plant cells communicate through cytoplasmic connections called

Answer 23

plasmodesmata

Question 24

Plasmodesmata form by _______________ following mitosis

Answer 24

incomplete separation of daughter cells