Ch. 10: Fibrous & Non-fibrous Proteins and Proteoglycans Flashcards Preview

Medical Biochemistry > Ch. 10: Fibrous & Non-fibrous Proteins and Proteoglycans > Flashcards

Flashcards in Ch. 10: Fibrous & Non-fibrous Proteins and Proteoglycans Deck (33):
1

What connective tissue cells synthesize proteins & proteoglycans?

Fibroblasts (general connective tissue)

Chondroblasts (cartilage)

Osteoblasts (bone)

2

Type I collagen: Locations? Disorders?

BONE, tendon, skin, dentin, facia, arteries

Osteogenesis imperfecta, Ehlers-Danlos syndrome (EDS)

3

Type II collagen: Locations? Disorders?

CARTILAGE, vitreous humor

Chondrodysplasia: spondyloepiphysial dysplasia, achondrogenesis, Stickler syndrome

4

Type III collagen: Locations? Disorders?

Skin, BLOOD VESSELS, uterus

EDS type IV

5

Type IV collagen: Locations? Disorders?

BASEMENT MEMBRANE

Alport syndrome: nephritis, sensorineural deafness

6

Type V collagen: Locations? Disorders?

Skin, placenta, blood vessels, chorion uterus

EDS types I, II

7

Ehlers-Danlos syndrome (EDS): 6 types?

Hypermobility
Classical
Vascular
Kyphoscoliosis
Arthrochalasia
Dermatosparaxis

8

Osteogenesis imperfecta (OI): types due to quantity of collagen? Quality of collagen?

Quantity: types I, III, IV

Quality: type II (death)

9

Scurvy: deficiency in which vitamin? effect on collagen?

Vit C

Compromise quality of collagen (problem with hydroxylating Pro & Lys)

10

Elastin: rich in which a.a.s? Locations?

Pro, Lys

Lungs, walls of large arteries, elastic ligaments

11

Describe elastin structure (2 things)

Tropoelastin interact with fibrillin

Desmosine cross links by lysyl oxidase

12

What is alpha1-antitrypsin?

Protease inhibitor (major role: inhibit neutrophil elastase)

Synthesized in liver, monocytes, and macrophages

13

Fxn of alpha1-antitrypsin in lungs?

Inhibits elastase ➡️ prevents alveolar wall damage

14

What happens in emphysema?

Alpha1-antitrypsin deficiency/destruction ➡️ elastase destroys elastin indiscriminately

15

What mutation causes 2-5% of emphysema? What type of inheritance?

E342K (Glu ➡️ Lys / GAG ➡️ AAG at 342)

Autosomal recessive

16

a.a. problem in smokers with alpha1-antitrypsin deficiency?

Inactive Met in alpha1-antitrypsin

17

What causes Marfan syndrome?

Defect in fibrillin gene

18

What are proteoglycans (mucopolysaccharides)?

Long, linear chains of glycosaminoglycans attached to core protein

19

What are the chains of proteoglycans made of?

Repeating disaccharide (➖ charge): hexoseamine + uronic acid

20

Fxn of proteoglycans?

Part of connective tissue (participate in organization of ECM)

21

Glycosaminoglycans: Hyaluronate

Composition?

D-glucosamine + D-glucuronate

No sulfate linkages

22

Glycosaminoglycans: Chondroitin sulfate

Composition?

D-galactosamine + D-glucuronate

23

Glycosaminoglycans: Dermatan sulfate

Composition?

D-galactosamine + L-Iduronate or D-glucuronate

24

Glycosaminoglycans: Keratan sulfate

Composition?

D-glucosamine + D-galactose (no uronic acid)

25

Glycosaminoglycans: Heparan sulfate

Composition?

D-glucosamine + D-glucuronate (major), L-iduronate (minor)

26

Glycosaminoglycans: Heparin

Composition?

D-glucosamine + L-iduronate (major), D-glucuronate (minor)

27

What are mucopolysaccharidoses (MPS)?

Genetic disorders of proteoglycan metabolism

Excessive accumulation & excretion of glycosaminoglycans

28

What causes mucopolysaccharidoses (MPS)?

Deficiencies of lysosomal enzymes (fxn: degrade proteoglycans)

29

MPS I H (Hurler), MPS I S (Scheie), MPS I H/S (Hurler/Scheie):

Enzyme deficiency? Glycosaminoglycan affected?

Alpha-L-iduronidase

Dermatan sulfate, heparan sulfate

30

MPS II (Hunter)

Enzyme deficiency? Glycosaminoglycan affected?

Iduronate sulfatase

Dermatan sulfate, heparan sulfate

31

Peptidoglycans: Made of? Part of?

Heteropolysaccharide chains cross-linked by short peptide chains

Bacteria cell walls; have antigenic determinants

32

Describe Gram ➕ bacteria

Cell wall: peptidoglycans & teichoic acids

33

Describe Gram ➖ bacteria

Peptidoglycans + outer membrane system external to plasma membrane, NO teichoic acids