Exam 2 - Glycocalyx and ECM

Question 1

What is the glycocalyx and what is it made of?

Answer 1

EC surface of cells; made of glycoproteins and glycolipids.

“Membrane decoration”

Question 2

What is the ECM secreted by?

Answer 2

Cells that interact with it.

Question 3

Is the ECM a part of the cell?

Answer 3

no

Question 4

What are glycoproteins?

Answer 4

Polypeptides conjugated to polysaccharides

Question 5

Which portion of the glycoprotein is associated with the membrane?

Answer 5

protein portion

Question 6

What determines the height and thickness of the glycocalyx?

Answer 6

Saccharide portion

Question 7

What are glycolipids?

Answer 7

Polysaccharides bound to membrane lipids

Question 8

What are the most complex glycolipids?

Answer 8

Gangliosides

Question 9

What is important about gangliosides?

Answer 9

They play a large role in immunology and are a receptor for bacterial toxins

Question 10

What are the 3 functions of the glycocalyx?

Answer 10

1. Protective barrier
2. Immune recognition of self
3. Intercellular adherence

Question 11

What does the glycocalyx protect the cell from?

Answer 11

Bacterial invasion

Question 12

What are two examples of glycocalyx functioning as intercellular adherence?

Answer 12

1. Early adhesion events during tissue formation

2. Blood clot formation

Question 13

What is the difference in structure between A/B antigens and O antigens?

Answer 13

A and B antigens are O antigens with additional saccharides attached to them.

Question 14

What are the 3 human blood group antigens?

Answer 14

A, AB, O

Question 15

What is the relationship between the glycocalyx and digestive enzymes?

Answer 15

Enzymes attach to the glycocalyx to digest food coming in

Question 16

What part of the glycocalyx increases the surface area of intestinal cells?

Answer 16

Height and density

Question 17

What does the glycocalyx on absorptive intestinal cells provide a barrier against?

Answer 17

Bacteria

Question 18

Why are antigen sampling cells more susceptible to Salmonella infection?

Answer 18

They sample inside of the gut

Question 19

Where does the H5N1 avian flu attach in birds?

Answer 19

Glycoproteins act as attachment sites in the mid-region of lungs

Question 20

How does the H5N1 avian flu spread from birds?

Answer 20

Can be coughed out

Question 21

Where does the H5N1 avian flu attach in humans?

Answer 21

Glycoproteins act as attachment sites deep in the lungs

Question 22

How does the H5N1 avian flu spread from humans?

Answer 22

It doesn’t; replicated virus cannot be coughed out

Question 23

Where are most animal cells embedded?

Answer 23

ECM

Question 24

What type of tissue is the ECM most prominent in?

Answer 24

Connective tissue

Question 25

What is the ratio of ECM to cells in c.t.?

Answer 25

ECM more plentiful than cells

Question 26

What are the 3 components of ECM in c.t.?

Answer 26

1. Fibers 2. GAGs (most attached to proteoglycans) 3. Other proteins

Question 27

What are proteoglycans?

Answer 27

Protein core with carb chains attached (GAG chains) | - There are many different types

Question 28

What largely determines the function of proteoglycans?

Answer 28

Associated GAG chains

Question 29

What are the 2 main functions of proteoglycans?

Answer 29

1. Attract water; provide well-hydrated matrix | 2. Withstand compressive forces

Question 30

What is an example of a GAG discussed in class?

Answer 30

Hyaluronic acid

Question 31

Where is hyaluronic acid found?

Answer 31

ECM in dermis

Question 32

What are the 2 functions of hyaluronic acid?

Answer 32

1. Pulls in water | 2. Helps to "plump up" skin

Question 33

What animal has an overproduction of hyaluronic acid and what happens?

Answer 33

Sharpei; wrinkled and slimy skin

Question 34

What are the 2 fiber types found in ECM?

Answer 34

1. Collagen | 2. Elastic

Question 35

Where is collagen synthesized and where is it assembled?

Answer 35

Synthesized in the cell; assembled extracellularly

Question 36

What determines the forces that can be tolerated by tissue?

Answer 36

Arrangement of collagen fibers

Question 37

Between dense irregular c.t. and dense regular c.t., which is strongest?

Answer 37

Dense irregular

Question 38

What is Ehlers-Danlos Syndrome?

Answer 38

Defect in collagen synthesis

Question 39

How does Ehlers-Danlos Syndrome present?

Answer 39

Cutis hyperelastica

Question 40

What is cutis hyperelastica?

Answer 40

Defect in collagen in the dermis

Question 41

What are elastic fibers made up of?

Answer 41

Network of elastin molecules

Question 42

What is the structure of elastic fibers when relaxed?

Answer 42

Fibers coiled and attached to one another

Question 43

What are 3 types of tissues/organs that have elasticity?

Answer 43

1. Skin 2. Aorta 3. Lung

Question 44

What breaks down elastin?

Answer 44

elastase

Question 45

Where is elastin found in the lungs?

Answer 45

Around alveoli

Question 46

What does excessive elastase production result in?

Answer 46

Emphysema; alveoli cannot contract when a breath is released