49. Fibrous proteins

Question 1

most abundant protein in the body

Answer 1

collagen

Question 2

collagen is stabilized by

Answer 2

hydrogen bonds

Question 3

long stiff extracellular structure in which 3 polypeptides (alpha chains) each 1000 AA in length are wound around each other in a triple helix

Answer 3

collagen

Question 4

most common form of collagen

Answer 4

type 1 collagen

Question 5

collagen is rich in these AA

Answer 5

glycine

proline

Question 6

this amino acid facilitates kinking

Answer 6

proline

Question 7

collagen is formed by these cells

Answer 7

fibroblasts
osteoblasts
chondroblasts

Question 8

type of collagen

Bone, skin, tendon

Answer 8

type I

Question 9

type of collagen

cartilage, vitreous body, nucleous pulposus

Answer 9

type II

Question 10

type of collagen

reticulin (skin), blood vessels

Answer 10

type II

Question 11

type of collagen

basement membrane or basal lamina

Answer 11

type IV

Question 12

type of collagen

beneath stratified squamous epithelium

Answer 12

type VII

Question 13

type of collagen

dentin, fascia, cornea, late wound repair

Answer 13

type I

Question 14

type of collagen

uterus, fetal tissue, granulation tissue

Answer 14

III

Question 15

group of inherited disorders characterized by :
hyperextensibility of the skin
abnormal tissue fragility
inc joint mobility

Answer 15

Ehlers- Danlos syndrome

Question 16

Defect in types I and V collagen

Answer 16

classical Ehlers- Danlos syndrome

Question 17

defect in type III collagen

Answer 17

Hypermobility Ehlers- Danlos syndrome

Vascular Ehlers- Danlos syndrome

Question 18

• joint hypermobility (less severe joint changes )

* severe skin abnormalities

Answer 18

classical

Question 19

• joint hypermobility
• skin abnormalities
• OA
• severe pain

Answer 19

hypermobility EDS

Question 20

most common EDS

Answer 20

hypermobility

Question 21

most serious EDS

Answer 21

vascular EDS

Question 22

• fragile blood vessels and organs
• small stature
• thin and translucent skin and easy bruising
• ÎÎ risk of intracranial aneurysms

Answer 22

vascular EDS

Question 23

brittle bone syndrome

Answer 23

osteogenesis imperfecta

Question 24

mutation in collagen genes that result to bones that is easily bend and fracture

Answer 24

osteogenesis imperfecta

Question 25

osteogenesis imperfecta | most common form

Answer 25

autosomal dominant with abnormal collagen type I

Question 26

* hematuria (main presenting sign) * ocular lesions * hearing loss * eventually ESRD

Answer 26

alport syndrome

Question 27

multiple fractures blue sclerae hearing loss dental imperfections

Answer 27

osteogenesis imperfecta

Question 28

the skin breaks and blisters as a result of minor trauma Dystrophic form is due to mutations affecting structure of type VII collagen - which ancors basal lamina and collagen fibrils in the dermis

Answer 28

epidermolysis bullosa

Question 29

hydroxylation of collagen is a post transltional modification requiring

Answer 29

ascorbic acid

Question 30

deficiency leads to dec cross-linking of collaen fibers

Answer 30

scurvy

Question 31

sore spongy gums loose teeth poor wound healing petechiae on skin and mucous membranes

Answer 31

scurvy

Question 32

characterized by kinky hair and growth retardation | dietary deficiency of copper

Answer 32

Menkes disease

Question 33

Menkes disease is a dietary deficiency of copper required by

Answer 33

lysyl oxidase

Question 34

connective tissue protein with rubber like properties responsible for extensibility and elastic recoil in tissues

Answer 34

elastin

Question 35

protein rich in proline mlysine, little hydroxyprolien and no hydroxylysine

Answer 35

elasin

Question 36

deposited into an irregular fibrillin scaffold cross-linked by desmosine

Answer 36

elastin

Question 37

mutation in fibrillin gene

Answer 37

marfan syndrome

Question 38

inheritance of marfan syndrome

Answer 38

Autosomal dominant

Question 39

* taller and thinner than family members * dolichostenomella * arachnodactyly * aortic dilation (70-80%) and dissection * upward dislocation of the lens (ectopia lentis)

Answer 39

marfan syndrome

Question 40

inhibits proteolytic enzymes from hydrolyzing and destroying protins

Answer 40

alpha-1 antitrypsin

Question 41

pathophysiology of alpha-1 antitrypsin deficiency

Answer 41

elastase destroys alveolar walls -> emphysema