Brainscape's Knowledge GenomeTM

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


See full index

BB10005 > Extracellular matrix > Flashcards

Extracellular matrix Flashcards

1
Q

What is the definition of an extracellular matrix?

A

Any substance produced by cells and secreted into the extracellular space within the tissues.

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

Why is the the ECM important?

A

It provides physical support for the cells and a linkage between different cells or tissues and also forms a substrate on which cells can move and it provides cues that guide the direction of movement.

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

What are connective tissues made up of?

A

It is mostly made up of ECM and consists of scattered cells such as fibroblasts.

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

What is the ECM in connective tissue made up of?

A

Collage fibre cross-linked by accessory proteins in a matrix of proteogylcans, which is protein and polysaccharides.

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

What is the structure of epithelial tissues?

A

It consists of scant ECM that is made up of layers of cells closely bound to one another to form protective sheets. The ECM is concentrated under epithelia to provide a base for the cells to sit on and acts as a molecular sieve and substrate for migrating cells.

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

What is the ECM in plants made up of?

A

Cellulose fibres that are cross-linked with hemicellulose in a matrix of highly branched polysarccharides, such as pectin.

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

What is the other name for the ECM in plants?

A

The cell wall.

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

How does plant ECM differ from animal ECM?

A

Animal ECM is made up of fibres from protein, such as collagen and elastin.

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

What percentage of the protein mass does collagen make up?

A

25%.

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

How many different collagen genes are there in mammals?

A

42.

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

How are collagen fibres formed?

A

Single strands of collagen form a triple stranded collagen molecule that is twisted together. Lots of these triple stranded collagen molecules form collagen fibrils, which then congregate to form collagen fibres.

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

What is type I collagen?

A

It forms long fibres.

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

What is type II collagen?

A

Networks are more mesh-like.

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

What is type VI collagen?

A

Bind collagen fibrils together to form thicker fibres.

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

What is type XI and V collagen involved in?

A

They co-assemble into fibres with type I collagen and regulate the structures and properties of the fibres.

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

What are the cross links between the components of tropocollagen?

A

Covalent cross links.

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

What are the cross links between fibrils and fibres?

A

Hydroxyproline cross-links.

18
Q

What is the amino acid repeat in collagen molecules?

A

GlycineXY where X and Y can be any amino acids, but are predominantly lysine, proline, hydroxylysine and hydroxyproline.

19
Q

What amino acids are the basis of cross-linking between the collagen molecules?

A

The hydroxified amino acids.

20
Q

How can collagen be kept in solution and prevent fibres and fibrils being formed?

A

THere is end that is now glyXY repeat (not triple helical).

21
Q

What is the importance of these collagen structures that do not form fibrils or fibres?

A

They are bundled up into secretory vesicles that are taken to the edge of the cell and fused with the plasma membrane and procollagen helices.

22
Q

What is the function of elastin?

A

It provides elasticity to tissues.

23
Q

What is elastin composed of?

A

Large filaments with lots of random coils that can be compared to springs. It is connected by cross-linked lysine or hydroxylysines.

24
Q

What happens when elastin stretches?

A

It flattens out, compared to its relaxed coiled state.

25
Q

How is the ECM in animals similar to that in plants?

A

Most of the matrix consists of polysarccharides.

26
Q

What is the protective structure in plant ECM and animal ECM?

A

In plants its pectin which forms a highly hydrated gel, whereas in animals its glycosaminoglycans (GAGS).

27
Q

What are some of the features of glycosaminoglycans?

A

It is highly negatively charged, hydrophillic and is linked to non-fibrous proteins such as proteoglycans. It is a disaccharide.

28
Q

Why do lots of different types of connective tissue exist?

A

There is variation in the proportion of fibres to cells within the ECM, there is varying numbers and proportions of different cell types within the ECM, there is varying proportions and arrangements of fibres in the ECM and there is varyinh composition of the non-fibrous component of the ECM.

29
Q

What are the specialised cell types of fibroblasts?

A

Osteocytes (bone)

30
Q

What are the specialised cell types of macrophages?

A

Chondrocytes (cartilage)

31
Q

What are the specialised types of mast cells?

A

Adipocytes (adipose/fat) and blood cells (blood)

32
Q

Why did Mr Morris have such stretchy skin?

A

There would have been failure of the conversion of lysine to hydroxylysine (by lysyl hydroxylase) or failure to cleave off propeptide termini, meaning that fibrils and fibres don’t form.

33
Q

What does areolar connective tissue contain?

A

Elastin and collagen fibres.

34
Q

What does adipose tissue contain?

A

Adipocytes and reticular fibres.

35
Q

What do tendons and ligaments contain?

A

Collagen fibres and fibroblast nuclei

36
Q

What does the dermis of the skin and organ joint capsules contain?

A

Fibroblast nuclei, and collagen fibres in varying orientations.

37
Q

What does elastic cartilage contain?

A

Chondrocyte in lacuna and elastin fibres.

38
Q

What does bone contain?

A

Osteocytes in lacuna.

39
Q

What is scurvy?

A

Vitamin C is a cofactor for prolyl hydroxylase to form hydroxyproline. This is needed to cross-link collagen, so the lack of this will cause abnornal fibrils resulting in fragility and bleeding.

40
Q

What is fibrodysplasia ossificans progressiva?

A

When muscle and connective tissue, such as tendons, are gradually replaced by bone.

BB10005 (22 decks)

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