Fibrous Proteins

Question 1

characters of fibrous proteins

Answer 1

dominating kind of secondary structure
long, narrow rod-like
low water solubility
role for tissue/cellular architecture

Question 2

Collagen structure

Answer 2

most abundant protein in body
rigid, insoluble
alpha chain has glycine - x - y repeats

Question 3

type 1 collagen

Answer 3

skin, bone, tendons, cornea

Question 4

type 2 collagen

Answer 4

cartliage, intervertebral disks, vitreous body

Question 5

type 3 collagen

Answer 5

blood vessels, dermis, lymph nodes, early would repair

Question 6

type 4 collagen

Answer 6

basement membranes
especially kidney

Question 7

type 5 collagen

Answer 7

most interstitial tisse
associated with type 1

Question 8

three biosynthesis processes for collagen

Answer 8

osteoblasts
chondroblasts
fibroblasts
outside of the RER is where collagen is secreted then cleaned up on the edges

Question 9

process of collagen production

Answer 9

precursor alpha chain in ER lumen
procollagen forms triple helix with loose ends in ER lumen
secretion out of cell via procollagen peptidase
Tropocollagen is then assembled with collagen fibrils outside of cell
collagen fibrils form into collagen fiber

Question 10

biosynthesis of collagen

Answer 10

pro alpha chains
hydroxylation where proline and lysine residues are hydroxylated with Vitamin C
glycosylation occurs with disulfide bonds, secretes as procollagen
extracellular removal of terminal extensions, creating tropocollagen
collagen fibril overlap to create stronger structure
cross linking by lysyl oxidase = tensile strength

Question 11

hydroxlyation at Proline and Lysine

Answer 11

requires ascorbic acid (Vitamin C) as coenzyme
interchain H bond formation and stable a triple helix

Question 12

Scurvy

Answer 12

vitamin C deficiency
bruises, petechiae, gum disease, loosen teeth
do to poor diet

Question 13

what is needed for cross linking by lysyl oxidase

Answer 13

Copper (cofactor)
PLP/B6 Vitamin (coenzyme)
the more cross links there are means more stiffer as age

Question 14

Disease collagen type 1

Answer 14

osteogenesis imperfecta, EDS

Question 15

Disease collagen type 3

Answer 15

EDS (vascular)

Question 16

Disease collagen type 4

Answer 16

Alport’s syndrome
goodpasture’s syndrome

Question 17

Disease collagen type 5

Answer 17

EDS

Question 18

Osteogenesis imperfecta

Answer 18

brittle bone, blue sclera

Question 19

Menke disease

Answer 19

steely hair, x link recessive with deficient cross linking and copper deficeincy

Question 20

composition of elastin

Answer 20

small nonpolar AA
rich in proline and lysine
little OH-Pro, OH-Lys
rubber like and connective tissue for elastic ligament

Question 21

synthesis of elastin

Answer 21

tropoelastin combine with microfibrillar protein including fibrillin 1

Question 22

elastin cross linking

Answer 22

catalyzed by lusul oxidase where 4 lysine are cross link into desmosine
desmosine is all eleastic properties

Question 23

keratin made up of

Answer 23

two pairs of alpha helices to form protofilament
these form intermediate filament
these form microfibrils then macrofibrils

Question 24

What makes up hair shape?

Answer 24

cysteine bonds in keratin

Question 25

Epidermolysis bullosa simplez

Answer 25

blister formation at dermoepidermal junction
due to mutation on gene for Keratin 5/14