More Carbs

Question 1

Glycosamines - where is hyaluronate found?

Answer 1

-In various connective and epithelial tissue

composed of glucuronic acid and nacetylglucosamine

Question 2

Where is chondroitin sulfate found?

Answer 2

-In ECM of cartilage and plays a role in absorbing shock

composed of gluronic acid and nacetylgalactosamine

Question 3

Where is keratan sulfate found?

Answer 3

-In bone and cartilage
-Shock absorber

cxomposed of galactose and nacetylglucosamine

Question 4

Where is heparin found?

Answer 4

Released by mast cells at site of injury and infection - acts as anticoagulant

composed of iduronic acid and

Question 5

What is heparin?
What is heparin sulfate?
What do they do?

Answer 5

Heparin is linear polymer, 3-40kDa
Heparin sulfate is heparin-like polysaccharide but attached to proteins
-Highest neg-charged density molecules
-Prevent blood clotting by activating protease inhibitor anti-thrombi
-Binding to various cells regulates development and formation of blood vessels
-Can also bind to viruses and bacteria to decrease their virulence

Question 6

What are proteoglycans? What do these break into?

Answer 6

Proteins that are attached to glycosaminoglycans

-Syndecans - protein has single transmembrane domain
-Glypicans - protein is anchored to a lipid membrane

Question 7

Whta is the functions of proteoglycans?

Answer 7

-Joint lubricants
-Structural components of CT
-Bind cells to the ECM
-Regulate movement of molecules through the matrix

Question 8

What are the main components of the ECM?

Answer 8

-Proteoglycan aggregates
-Collagen fibers
-Elastin

Question 9

What do some tumour cells secrete to degrade ECM?

Answer 9

Heparinase

Question 10

What are integral membrane proteins that act as receptors for extracellular proteoglycans called?

Answer 10

Integrins
-Link cellular cytoskeleton to ECM and transmit signals to cell to regulate

Question 11

How is a carbohydrate attached to a protein?

Answer 11

Via its anomeric carbon to amino acids on the protein

-Common at serine, threonine, asparagine
-Only some bacteria glycosylate a few of their proteins

Question 12

What helps viral proteins evade the immune system?

Answer 12

-Viral proteins are heavily glycosylated

Question 13

What are ABO blood group types determined by?

Answer 13

-Glycoprotein head group
-Absence or presence of diff sugar molecule determines ABO blood group types

Question 14

What alleles are i) A and ii) B found on?

Answer 14

A = allele 1
B = allele 2