bio L6

Question 1

what is the Basic components of ECM ?

Answer 1

structural proteins
proteoglycans
adhesion proteins

Question 2

what is the main structural proteins of connective tissue ?

Answer 2

Collagens, elastin and laminin

Question 3

what Proteoglycans form ?

Answer 3

the gel oF ECM

Question 4

WHERE we can found the Proteoglycans ?

Answer 4

interstitial connective tissue
( synovial fluid cartilage )

Question 5

what are the proteins in the matrix ?

Answer 5

collagen, elastin, fibronectin, laminin

Question 6

Proteoglycans consist of what ?

Answer 6

of polysaccharide called glycosaminoglycans (GAGs) linked to a core protein

Question 7

glycosaminoglycans (GAGs) composed of what ?

Answer 7

repeating units of disaccharides

Question 8

Proteoglycans Interact with variety of proteins in the matrix

Answer 8

.

Question 9

what are the sugars that compose GAGs ?

Answer 9

N-acetylated (amino sugar)
acidic sugar

Question 10

A single exception is keratan sulfate, which contains galactose rather than an acidic sugar.

Answer 10

.

Question 11

The amino sugar is either D-glucosamine or D-galactosamine, in which the amino group is usually acetylated, eliminating its positive charge

Answer 11

.

Question 12

what give GAGs their strongly negative nature ?

Answer 12

carboxyl groups and the sulfate groups

Question 13

The acidic sugar is either D-glucuronic acid or epimer L-iduronic acid

Answer 13

.

Question 14

how the hydrated gel formed ?

Answer 14

the protoglycan have a negatively charged bind positively charged ions and formed hydrogen bonds with trapped molecules

Question 15

what is the functions of the gel of ECM ?

Answer 15

• provides a flexible mechanical support for ECM
• acts as a filter: allows the diffusion of ions

slows diffusion of proteins and movement of cell

      - acts as a lubricant

Question 16

what is the only GAG occurring as a single long polysaccharide chain and not sulfated

Answer 16

Hyaluronan

Question 17

where is the GAGs distributed ?

Answer 17

in the connective, epithelial, and neural tissues

Question 18

why the disaccharide chains tend to be extended in solution ?

Answer 18

Because of the high concentration of negative charges (they repel )

Question 19

WHY GAGs contributes to the resilience of cartilage, synovial fluid,

Answer 19

Because of the repulsion force between their negative charges, liquids containing GAGs return to their normal size after being compressed.

Question 20

GAGs are linked to proteins (except for hyaluronic acid)

Answer 20

.

Question 21

how the proteoglycan aggregates formed ?

Answer 21

many proteoglycan associate with one molecle of hyaluronic acid

and that occurs primarily
through ionic interactions between the core protein and the
hyaluronic acid. and it stabilized by link proteins ?

Question 22

The ECM has the ability to prevent cells from migrating to surrounding cells
Infection coefficient works to change the containing
cancer can wrok only by making chanings on the matrix

Answer 22

.

Question 23

how Disease like rheumatoid arthritis and osteoarthritis effect the body ?

Answer 23

by involve damage to the functional capacity of the matrix

Question 24

Alterations in the matrix of the renal glomerulus  allows proteins to be excreted into urine

Answer 24

.

Question 25

final structure of the proteoglycan resembles what ?

Answer 25

resembles a bottlebrush, with many GAG chains extending from the core protein