Brainscape's Knowledge GenomeTM

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


See full index

Biochem > Extracellular Matrix & Connective Tissue > Flashcards

Extracellular Matrix & Connective Tissue Flashcards

1
Q

The following describes the structure of what biomolecule found in the extracellular matrix:
found in synovial fluid of joints, arterial walls, bone and cartilage, and the ocular vitreous humor.

A

proteoglycans

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

Proteoglycans interact with proteins in the matrix such as collagen and elastin, fibronectin, and laminin. Collagen and elastin play ___ roles. Fibronectin is involved in cell ___ and ___.

A

structural; adhesion, migration

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

Proteoglycans consist of a ___ protein covalently attach to many long, linear chains of _____.

A

core; glycosaminoglycans

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

Glycosaminoglycans are made of repeating ____ units. These repeating units usually contain a ____ and an ___ acid. These sugars are frequently sulfated. Therefore they repel each other (due to negative charge) and act as a lubricant.

A

disaccharide; hexosamine, uronic

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

Proteoglycans occupy a very large space and act as “molecular ____”. These properties give some flexibility to substances such as cartilage, compression and re-expansion

A

sieves

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

There are at least seven types of glycosaminoglycans, which differ in the monosaccharides present in their repeating disaccharide units. Name all 7.

A 
chondoritin sulfate
dermatan sulfate
heparan
heparan sulfate
hyaluronic acid
keratan sulfate I
keratan sulfate II
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

All glycosaminoglycans except ___ ___ are attached to proteins by covalent linkage to serine or threonine residues.

A

hyaluronic acid

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

Keratan sulfate I is attached via ____ residues

A

asparagine

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

Once the protein enters the ER, synthesis of the proteoglycans starts with the attachment of a ___ to serine or threonine residues of the protein

A

sugar

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

____-sugars are the substrates for proteoglycan synthesis

A

UDP

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

Specific UDP-sugar ________ are responsible for sequential transfer of monosaccharides from a nucleotide-linked sugar to an appropriate acceptor

A

glycosyltransferases

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

Sulfate groups are added through N- and O-sulfation, and they occur after the addition of sugars. What provides the sulfate groups for this reaction?

A

PAPS

3’ phosphoadenosine 5’

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

Once the synthesis of the proteoglycan is complete, it is secreted and forms the ___ ____

A

extracellular matrix

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

Proteoglycan ___ is formed by nonequivalent interaction between core protein and hyaluronic acid

A

aggregate

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

What is the function of hyaluronic acid?

A

cell migration, embryogenesis, morphogenesis, wound healing

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

What is the function of chondroitin sulfate?

A

formation of bone, cartilage, cornea

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

What is the function of keratan sulfate?

A

transparency of cornea

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

What is the function of dermatan sulfate?

A

transparency of cornea, binds LDL to plasma wall

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

What is the function of heparin?

A

anticoagulant, releases lipoprotein lipase from capillary walls

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

What is the function of heparan sulfate

A

component of skin fibroblast and aortic wall, commonly found on cell surfaces

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

The following describes the structure of what biomolecule:
usually contain shorter carbohydrate chain than proteoglycans, The carbohydrate moiety is often branched and is not made of repeating disaccharides. Most circulating proteins in the blood are this biomolecule

A

glycoproteins

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

In synthesis of glycoproteins, carbohydrate monomers are added to the protein in the lumen of ER and the golgi complex. In most cases, the initial sugar is added either through O-linkage to ___ or ___ residues, or N-linkage to an ___ residue.

A

serine; threonine; asparagine

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

In regards to O-linked glycosides, glycosylation of the protein begins with the attachment of an __________ onto a specific serial or threonyl side chain of the protein

A

N-acetyl-galactosamine

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

In regards to O-linked glycosides, glycoproteins that are destined to plasma membrane will be integrated to the Golgi membrane with glycosyl moiety facing the ___ lumen.

A

Golgi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In regards to O-linked glycosides, glycoproteins that are destined to be secreted from the cell remain ___ in the lumen. ___ vesicles bud off the Golgi and fuse with the cell membrane releasing the glycoproteins to the extracellular space

A

free; secondary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In regards to N-linked glycosides, the protein itself does not become glycosylated with individual sugars; instead a lipid-linked _______ is first constructed.

A

oligosaccharide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

In regards to N-linked glycosides, after the oligosaccharide is constructed, the sugars are then added by the membrane-bound _______

A

glycosyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Oligosaccharides are transferred from the dolichol to asparagine residues of the protein by a ____-_____ transferase enzyme present in the ER

A

protein-oligosaccharide

29
Q

Lysosomal enzymes degrade proteoglycans and glycoproteins bought into the cell by the process of ____

A

endocytosis

30
Q

The carbohydrate moiety is degraded by the lysosomal ____

A

glycosidases

31
Q

______ cleave carbohydrate chains to shorter oligosaccharides
_____, specific for each type of linkage, remove the sugar residue from the nonreducing end

A

endoglycosidases; exoglycosidases

32
Q

All collagen types have a ____ ____ structure

A

triple helical

33
Q

Each polypeptide subunit or alpha chain of collagen is twisted into a ___-handed helix of three residues per turn

A

left

34
Q

Three alpha chains are then wound into a ___-handed superhelix. ____ bonding stabilizes this triple helix.

A

right; hydrogen

35
Q

______ residues occur at every third position of the triple helical portion of the alpha chain

A

glycine

36
Q

____ and ____ residues as X and Y in Gly-X-Y increase rigidity of the collagen

A

proline; hydroxyproline

37
Q

Collagen is synthesized as a ____, which contains a signal sequence and polypeptide extensions

A

preprocollagen

38
Q

In regard to collagen synthesis, extension peptides contain ___ residues

A

cysteine (disulfide bridges)

39
Q

Hydroxyproline is formed post-transcriptionally by hydroxylation of the proline residues by a ___ ___ enzyme. The enzyme requires ascorbic acid and alpha ketoglutarate as cofactors

A

prolyl hydroxylase

40
Q

Lysine and hydroxylysine can participate in the __ position in Gly-X-Y

A

Y

41
Q

Several collagen types do not form fibrils in tissues. They are characterized as “____” of the triple helix with stretches of protein lacking Gly-X-Y repeat structures

A

interruptions

42
Q

Collagen ___ is the best known example of collagens with discontinuous triple helices

A

IV

43
Q

Where is Type I collagen found?

A

skin, bone, tendon, blood vessels, cornea

44
Q

Where is type II collagen found?

A

cartilage, intervertebral disk, nitrous body

45
Q

Where is type III collagen found?

A

blood vessels, fetal skin

46
Q

Where is type IV collagen found?

A

basement membrane

47
Q

Where is type V collagen found?

A

same as type I

48
Q

This syndrome comprises a group of inherited disorders whose principal clinical features are hyper extensibility of the skin, abnormal tissue fragility, and increased joint mobility.

A

Ehlers-Danlos syndrom

49
Q

Type ___ Ehlers-Danlos syndrome is the most serious because of its tendency for spontaneous rupture of arteries of the bowel, reflecting abnormalities in collagen III.

A

IV

50
Q

Type ____ Ehlers-Danlos syndrome is due to lysl hyroxylase deficiency. Patients exhibit marked joint hyper mobility and tendency to ocular rupture

A

VI

51
Q

Type ___ Ehlers-Danlos syndrome is due to procollagen N-proteinase deficiency, causing formation of abnormal thin, irregular collagen fibrils, manifested by marked joint hyper mobility.

A

VIIC

52
Q

This syndrome is referred to a group of genetic abnormalities affecting the structure of type IV collagen fibers. Patients are represented with hematuria and may eventually develop end-stage renal disease due to basal membrane abnormalities.

A

alport syndrom

53
Q

Scurvy affects the structure of collagen due to a deficiency in what vitamin?

A

vitamin C

54
Q

What are the major signs of scurvy?

A

bleeding gums, subcutaneous hemorrhages, and poor wound healing (due to deficiency of prolyl and lysyl hydroxylase activity)

55
Q

___ is a connective tissue that is responsible for properties of extensibility and elastic recoil in tissue

A

elastin

56
Q

Elastin is synthesized in a single ___ molecule.

A

tropoelastin

57
Q

True or false?

elastin does not have extension peptides, Gly-X-Y arrangement, triple helical structure, or carbohydrate moiety

A

true

58
Q

____ are the major cross-links of elastin

A

desmosines

59
Q

Deletions in elastin gene have been found in 90% of subjects with ___ syndrome, a developmental disorder affecting connective tissue and the CNS

A

williams

60
Q

Mutations effecting the synthesis of elastin probably play a causative role in the supravalvular ___ ____ often found in this condition

A

aortic stenosis

61
Q

Fibrillin is a large glycoprotein found in many tissues. It is secreted into the extracellular matrix by ____

A

fibroblasts

62
Q

This is an autosomal dominant disease affecting connective tissue. Most patients exhibit long digits and hyperextensibility of the joints, and cardiovascular problems

A

marfan syndrom

63
Q

Marfan syndrome is due to a mutation in the ___ gene

A

fibrillin

64
Q

This is a soluble glycoprotein found in large amounts in the extracellular matrix. It is a dimer, joined by disulfide bonds near their terminal

A

fibronectin

65
Q

Fibronectin receptor belongs to a family of transmembrane ___ class of proteins

A

integrin

66
Q

Fibronectin contains Arg-Gly-Asp sequence that binds to integrin. True or false?

A

true

67
Q

This consists of a3 distinct elongated polypeptide chains linked to together to form an elongated cruciform shape. It has a binding site for type IV collagen, heparan, and integrin on the cell surface

A

laminin

68
Q

What are the three primary components of the basal lamina?

A

laminin, entactin, and type IV collagen

Biochem (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions