Final Exam - Glycocalyx and ECM

Question 1

Where is glycocalyx found?

Answer 1

extracellular surface of the cells; membrane decoration

Question 2

What are the functions of glycocalyx?

Answer 2

• protective barrier from bacterial invasion
• immune recognition of self
• intercellular adherance

Question 3

How does glycocalyx execute its function of immune recognition of self?

Answer 3

specific glycoproteins deflect immune system from normal cells

Question 4

When is glycocalyx involved in intercellular adherance?

Answer 4

• early adhesion events during tissue formation

- blood clot formation

Question 5

What is the structure of a glycoprotein?

Answer 5

a membrane protein with a polysaccharide attached to it

Question 6

True or False: there is only one type of glycoprotein

Answer 6

False: different cell types have different polysaccharides linked to them

Question 7

What is the structure of a glycolipid?

Answer 7

a glycoprotein with a lipid connected to the polysaccharides

Question 8

How does the avian flu take advantage of glycocalyx?

Answer 8

specific glycoproteins act as an attachment site for H5N1

Question 9

Where does H5N1 attach in birds?

Answer 9

in the mid region of the lungs

Question 10

Where does H5N1 attach in humans?

Answer 10

deep in the lungs

Question 11

What is glycocalyx made up of?

Answer 11

glycoproteins and glycolipids

Question 12

What is the difference between O, A, and B blood antigens?

Answer 12

A and B are both similar to O, but they have different sugars attached to them

Question 13

What attaches to glycocalyx in the intestines?

Answer 13

digestive enzymes

Question 14

What is the structure of M cells?

Answer 14

they are shorter and sparser making them more susceptible to salmonella

Question 15

Where are most animal cells embedded in?

Answer 15

the extracellular matrix

Question 16

What is the structure of the extracellular matrix?

Answer 16

basement membrane and interstitial matrix

Question 17

What tissue type is the extracellular matrix most prominent in?

Answer 17

connective tissue

Question 18

What are the components of the extracellular matrix in connective tissue?

Answer 18

Glycose amino glycans (GAGS), hyaluronic acid, collagen, elastic fibers

Question 19

What is the structure of a glycose amino glycans?

Answer 19

proteoglycans - protein core with carbohydrate chains

Question 20

What are the functions of proteoglycans?

Answer 20

• attract water, provide a well hydrated matrix
• withstand compressive forces
• cell migration during development and repair
• filtration function in certain tissues
• binding sites for other molecules
• attachment to fibrous elements

Question 21

What is the function of hyaluronic acid?

Answer 21

pulls water into the extracellular matrix in the dermis plumping up the skin

Question 22

What is collagen?

Answer 22

a family of proteins, fibers made of collagen molecules

Question 23

Where is collagen synthesized?

Answer 23

inside the cell

Question 24

Where is collagen assembled?

Answer 24

extracellularly

Question 25

What is important about the arrangement of collagen fibers?

Answer 25

the arrangement of fibers determines forces that can be tolerated by tissue

Question 26

What are elastic fibers?

Answer 26

network of elastin molecules

Question 27

What do elastic fibers provide?

Answer 27

tissue elasticity; especially in the skin, aorta and lung

Question 28

What does over production of hyaluronic acid cause?

Answer 28

wrinkly skin, especially in shar peis, makes the skin too plump

Question 29

What is the cause of Ehlers-Danlos syndrome?

Answer 29

defect in collagen synthesis

Question 30

How can Ehlers-Danlos syndrome present?

Answer 30

cutis hyperelastica - stretchy skin

Question 31

What can excessive elastase production cause?

Answer 31

emphysema