Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Personal PoM MBC > extracellular matrix > Flashcards

extracellular matrix Flashcards

1
Q

what is the ECM?

A

a complex network of proteins and carbohydrates filling spaces between cells
comprises of both fibrillar and non fibrillar components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the ECM key functions?

A

physical support
determines mechanical and physiochemical properties of the tissue
influences the growth, adhesion and differentiation status of the cells and tissues with which it interacts
essential for development, tissue function and organogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the components of connective tissue?

A 
collagens
type I-III(fibrillar)
type IV(basement membrane)

multi-adhesive glycoproteins
fibronectin, fibrinogen
laminins(basement membrane)

proteoglycans
aggrecan, versican, decorin
perlecan(basement membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the collagens in connective tissue?

A 
type I-III(fibrillar)
type IV(basement membrane)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the multi-adhesive glycoproteins in connective tissue?

A

fibronectin, fibrinogen

laminins(basement membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the proteoglycans in connective tissue?

A

aggrecan, versican, decorin

perlecan(basement membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the properties of tendon and skin?

A

tough and flexible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the properties of bone?

A

hard and dense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the properties of cartilage?

A

resilient and shock absorbing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is osteogenesis imperfecta caused by?

A

type I collagen mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is marfan’s syndrome caused by?

A

fibrillin 1 mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is alport’s syndrome caused by?

A

type IV collagen mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is epidermolysis bullosa caused by?

A

laminin 5 mutation in all 3 chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is congenital muscular dystrophy caused by?

A

laminin 2 mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is hurler’s syndrome caused by?

A

alpha-L-iduronidase (enzyme used to degrabe glycosaminoglycns)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are some fibrotic disorders due to excessive ECM deposition?

A

liver fibrosis-cirrhosis
kidney fibrosis- diabetic nephropathy
lung fibrosis- idiopathic pulmonary fibrosis(IPF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is osteoarthritis caused by?

A

loss of ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is type I collagen’s composition?

A

[alpha1(I)]2 [alpha2(I)]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is type II collagens composition?

A

[alpha1(II)]3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is type III collagens composition?

A

[alpha1(III)]3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

outline the collagen triple helix

A

gly-x-y repeat in each chain (glycine has small side chain so can fit in gaps)
fibrillar collagen chains form a left handed helix
three chains form a triple helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

outline the makeup of collagen fibres

A

single collagen polypeptide chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

outline collagen biosynthesis

A

procollagen (with non-collagenous domains at N and C termini)—-> domains removed for fibrillar collagens but remain for most of the rest—-> collagen forms fibrils—-> fibrils cross link to form fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what causes the covalent cross link between collagen?

A

lysine and hydroxy-lysine involved

type and extent is tissue specific and changes with age

25
Q

what do prolyl and lysyl hydroxylases require?

A

Fe2+ and vitamin C

26
Q

what is scurvy caused by?

A

vitamin C deficiency resulting in under hydroxylated collagens reducing stability for tissue

27
Q

what are ehlers-danlos syndromes?

A

group of inherited connective tissue disorders

symptoms include loose joints and stretchy skin

28
Q

what do collagen types IX and XII do?

A

do NOT form fibrils but associate with fibrillar collagens and regulate the organisation of the collagen fibrils

29
Q

what does type IV collagen do?

A

network forming present in all basement membranes

30
Q

outline collagen type IV assembly

A

monomer(single strand)——>dimer(2 strands)—–>tetramer(3 strands)—–>supramolecular aggregate( many strands)

31
Q

what are basement membranes (basal laminae)

A

flexible thin mats of ECM underlying epithelial sheets and tubes
highly specialised containing a distinct repertoire of collagens, glycoproteins and proteoglycans

32
Q

what do basal laminae surround?

A

muscle, peripheral nerve, fat cells and underlie most epithelia

33
Q

what does the glomerular basement membrane do(GBM)?

A

in the kidney it forms a key part of the filtration unit

34
Q

where are elastic fibres found ?

A

elastic tissues

skin, blood vessels and lungs

35
Q

what are elastic fibres made from?

A

an elastin protein core and microfibrils which are rich in fibrillin

36
Q

outline symptoms of marfan’s syndrome

A

skeletal, ocular and cardiovascular systems primarily affected
predisposed to aortic ruptures
arachnodactyly (spider like fingers)

37
Q

outline the structure of elastin

A

two types of segments that alternate (hydrophobic regions and alpha-helical regions) with cross linked side chains

38
Q

outline what modular architecture means

A

proteins composed of characteristic domains of 50-200 amino acids
this is what allows them to be multi-purpose

39
Q

outline the structure of laminins

A

heterotrimeric proteins alpha, beta and gamma chain
form a cross shaped molecule
very large

40
Q

what can laminins do?

A 
multi adhesive ( integrins and dystroglycan)
can self associate or interact with components such as type IV collagen, nidogen and proteoglycans
41
Q

how can fibronectins exist?

A

insoluble fibrillar matrix
or
soluble plasma protein

42
Q

what can fibronectins do?

A

multi adhesive
interact with cell surface receptors and other matrix molecules
regulate adhesion and migration
wound healing

43
Q

what are proteoglycans?

A

core proteins that are covalently attached to glycosaminoglycan chains

44
Q

what are glycosaminoglycans(GAGs) made from?

A

repeating disaccharide units
one sugar in each disaccharide being an amino sugars
usually GAGs are sulphated or carboxylated (negative charge)

45
Q

what doe the negative charge of GAGs cause?

A

Na+ to be attracted which draws water into the ECM

46
Q

what are the families of proteoglycans? (4)

A

basement membrane proteoglycans
aggregating proteoglycans
small leucine-rich proteoglycans
cell surface proteoglycans

47
Q

what is perlecan?

A

a basement membrane proteoglycan

48
Q

what is aggrecan?

A

an aggregating proteoglycan( interacts with hyaluronan)

49
Q

what is decorin?

A

a small leucine-rich proteoglycan

50
Q

what are syndecans 1-4?

A

cell surface proteoglycans

51
Q

what gives cartilage good tensile strength?

A

has a matrix rich in collagen with large amounts of GAGs in the meshwork

52
Q

what are the GAG chain groups?(4)

A

hyaluronan
chondroitin sulphate and dermatan sulphate
heparan sulphate
keratan sulphate

53
Q

how is hyaluronan made?

A

spun out directly from an enzyme embedded in the plasma membrane

54
Q

what monomers make up hyaluronan?

A

glucuronic acid and N-acetylglucosamine

55
Q

what happens to the GAGs in aggrecan?

A

they are highly sulphated

56
Q

why are cations attracted to aggrecan?

A

because of the sulphated GAGs and the carboxyl groups

57
Q

what happens when aggrecan is compressed?

A

water is given up but regained when load is reduced

58
Q

outline osteoarthritis

A

results from excessive ECM degradation
cushioning properties at end of cartilage is lost
loss of aggrecan

59
Q

what happens when excess fibrous connective tissue is produced?

A

fibrotic diseases

damages structures

Personal PoM MBC (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions