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Flashcards in Biochem: Matrix Proteins Deck (31):
1

Type of collagen found in blood vessels and fetal skin.

Type III

2

Type of collagen found in skin, bone, tendon, blood vessels, cornea

Type I

3

Type of collagen found in basement membranes.

Type IV

4

Type of collagen found in cartilage, IV disc, and virtreous body

Type II

5

Role of Vitamin C in collagen synthesis.

Co-factor for hydroxylation of proline and lysine residues
-the OH functional groups allow hydrogen bonding between helices of collagen units to make the structure stronger

6

Pathogenesis of Menkes Syndrome

X-linked recessive mutation in Copper-Binding ATPase
-prevents adequate uptake of copper from the diet
-copper is needed for the enzyme lysine oxidase, without it tropocollagen units do not cross-link well and the patient usually dies in infancy

7

Pathogenesis of Osteogenesis Imperfecta.

Autosomal dominant mutation in genes required for Type 1 collagen production. Type 1 collagen is either absent or in reduced amounts. Characteristic blue sclera (blue color comes from blood in the choroid veins, the sclera is thinner in this disease making the color more visible)

8

Mildest form and most severe form of Osteogenesis Imperfecta.

Mildest: Type 1
Most severe: Type 2

9

Pathogenesis of the most common type of Ehlers Danlos Syndrome.

Type 3
-mutation in the gene encoding Tenascin-X
-results in Hypermobile Joints

10

Pathogenesis of Type 1 and 2 Ehlers Danlos

Abnormal Type V collagen formation

11

Pathogenesis of Type 4 Ehlers Danlos

Mutation in genes encoding Type III collagen
-vascular condition with a high risk of blood vessel rupture

12

Pathogenesis of Dystrophic Epidermolysis Bullosa (DEB).

Mutation in the gene that encodes Type VII collagen resulting in blisters and breaks in the skin

13

Pathogenesis of Alport Syndrome.

Gene mutation in Type IV collagen production
-leads to abnormal formation of basement membranes
(multiple genes can mutate and result in this condition)

14

Major complication of Alport Syndrome

Renal Failure in early adult life

15

Component of elastin connective tissue that gives it strength.

Cross-linking of lysine residues in elastin chains forming structures called Desmosines

16

Major complication and pathogenesis of William Syndrome.

Supravalvular Aortic Stenosis
-deletion of multiple genes on Chromosome 7
-results in a deficiency of elastin causing unstable blood vessels
-other sequelae include: elfin facial appearance, very trusting personality

17

Complication of Alpha-1 Antitrypsin deficiency.

Emphysema
-the enzyme is needed to inactivate elastases
-without A-1A, elastases are overactive and degrade elastin in alveolar tissue

18

Main connective tissue function of Fibrillin

Polymerizes to form scaffolding for elastin deposition

19

Gene mutated in Marfan Syndrome

Fibrillin-1 gene

20

Main function of Fibronectin.

Component of the extracellular matrix that "glues" cells together

21

Obstetric application for Fibronectin

Fetal Fibronectin Test
-fibronectin is used to hold the amniotic sac to the uterus in pregnancy
-if fetal fibronectin levels are raised from a cervical swab, it could indicate higher risk of preterm labor

22

Pathogenesis of Junctional Epidermolysis Bullosa.

Defect in laminin in skin
-results in instability of the dermoepidermal junction
-blistering of skin and mucous membranes

23

Pathogenesis of Congenital Muscular Dystrophy.

Defect in laminin in muslces
-results in instability of the muscle cell cytoskeleton-extracellular matrix link
-muscle weakness

24

Most abundant Glycosaminoglycan (GAG)

Chondroitin Sulphate
-present in cartilage, tendon, bone, ligaments, cornea

25

GAG that plays a role in corneal transparency

Keratan Sulphate I

26

GAG involved in anticoagulation

Heparin

27

GAG involved in synovial fluid of joints and vitreous humor

Hyaluronic Acid

28

General Pathogenesis of Mucopolysaccharidoses

Deficiency in lysosomal enzymes that degrade GAGs

29

Mucopolysaccharidosis that involves corneal clouding, stiff joints, Aortic Valve disease, normal intelligence, and normal lifespan

Scheie Syndrome

30

Mucopolysaccharidosis that involves mental retardation, corneal clouding, dwarfing, and early death due to depositions in coronary arteries

Hurler Syndrome

31

Mucopolysacharidosis that involves mental retardation, physical deformity, no corneal clouding

Hunter Syndrome