Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry Final Exam > Collagen Structure and Function (1 + 2) > Flashcards

Collagen Structure and Function (1 + 2) Flashcards

1
Q

What proteins does the stromal matrix of connective tissue contain?

A

hyaluronan
proteoglycans
glycosaminoglycans

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

What inherited disease is due to mutations in the COL7A1 gene, resulting in fragile skin that blisters easily and can be sloughed off?

A

dystrophic epidermis bullosa

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

Collagen arranged in parallel bundles would be found in what tissue?

A

tendons and ligaments

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

What are the functions of extracellular matrix in cartilage?

A
  • support and locomotion

- resilient shock absorber

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

Which protein cleaves the C-terminal peptide off of the procollagen molecule?

A

BMP1

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

The ____ refers to the basal lamina combined with the layer of tethering collagen fibrils.

A

basement membrane

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

What collagens make up the non-fibrillar collagens (major and minor)?

A

IV, VI, VII, VIII, IV, X, XII, XII-XXIII, XXV, XXVI, XXVIII

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

Which protease is responsible for cleaving off the N-propeptide?

A

ADAMTS2, 3, 14

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

What are the main steps of collagen biosynthesis or assembly?

A
  • synthesis of a pro-a chain
  • formation of a procollagen triple helix
  • formation of procollagen trimer
  • formation of tropocollagen
  • aggregations of collagen fibrils form collagen fiber
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Type __ collagen is found only in the narrow zone at the DEJ; Type __ collagen is found in the enamel organic matrix adjacent to DEJ.

A

IV; VII

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

___ accelerates protein folding during collagen biosynthesis.

A

FKBP10 (peptidyl prolyl cis-trans isomerase)

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

What is the primary role of type VII (7) collagen in both the basal lamina AND at the DEJ?

A

anchoring

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

Which proteins act in lysyl hydroxylation in collagen biosynthesis?

A

PLOD2

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

What are the key components of the basal lamina?

A
  • Glycoproteins (laminins, nidogen)
  • Collagens (IV)
  • Proteoglycans (perlecan)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Collagens arranged in a swirling pattern around dentinal tubules are found where?

A

in teeth

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

In most connective tissues, ____ secrete the extracellular matrix.

A

fibroblasts

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

____ syndrome leads to issues with kidney filtration, blood in urine, burning sensation while urinating, and nephritis, eventually leading to acute renal failure.

A

Goodpasture

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

Which fibers of the periodontal ligament are obliquely-positioned and located in the middle of the root?

A

oblique fibers

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

In those forms of OI where the Type I collagen genes themselves were not mutated, what could you suspect to be the cause of these types of OI?

A

potentially issues or mutations in the post-translational modifications of pro-collagen processing

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

In what syndrome are there autoantibodies produced against the Type IV collagen alpha-3-chain?

A

Goodpasture

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

What is the other form of OI that actually express no mutations in collagen genes?

A

Type V OI

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

Which type of collagen regulates the spacing of Type II collagen fibrils?

A

Type XI

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

The ___ separates epithelium from the underlying connective tissue stroma and is primarily made up of Type IV collagen.

A

basal lamina

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

The ___ is composed of many proteins with various properties assembled into an organized network/meshwork, often associated with producer cells.

A

extracellular matrix

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

What type of collagen found in teeth is the major ECM component of dentin, cementum, the the periodontal ligament (PDL)?

A

Type I collagen

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

What component of ECM accounts for tensile strength?

A

collagen (fibrillar component)

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

What enzyme in collagen biosynthesis catalyzes the formation of interchain disulfide bonds between cysteines during the nucleation of the polypeptide chains?

A

PDI (protein disulfide isomerase)

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

Type __ collagen is important in dermal reticular fibers, along with small amounts in dentin.

A

III (with V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What type of experiment would you conduct if you found two diseases to have a very similar phenotype but associate with completely different genes?

A

conduct an experiment to determine if these totally different genes interact with a common pathway at some point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When can fibril formation occur in collagen biosynthesis?

A

after the C and N propeptides have been removed from procollagen to form tropocollagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What specialized matrix separates connective tissue stroma and epithelium?

A

basal lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the secondary structure collagen helix stabilized by?

A

static repulsion of pyrrolidone rings of proline and hydroxyproline residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which types of OI have no mutations in Type I collagen genes?

A

V and VI-XVI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What layer of connective tissue is important in cell polarity?

A

basal lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Which type of EDS is unique in that its mutations are located in the N-terminal protease cleavage sites of collagen biosynthesis?

A

Arthrochalasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Type __ collagen may regulate the assembly of type II collagen fibrils.

A

IX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Is the banding in fibrillar collagen lightly or darkly stained where there are no gaps in the collagen molecules?

A

light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Mutations in COL4A are associated with what disease?

A

Alport syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What happens when CRTAP is mutated?

A

mutations in CRTAP cause defective prolyl-3-hydroxylation which delays collagen folding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Collagen, elastin, and fibrillin are ____ proteins.

A

structural

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are some characteristics of achondrogenesis type II?

A
  • hypercellular epiphyseal cartilage
  • poor or absent growth plate
  • diminished ECM
  • thick irregular collagen fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What material makes up the majority of dentin?

A

collagen (mostly Type I, with some III and V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What type of fibrous proteins help cells attach to ECM?

A

adhesive (fibronectin, vitronectin, laminin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

In polypeptide nomenclature, where is the collagen type noted?

a1(II)

A

at the (II)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What enzyme glycosylates selected hydroxylysines in the synthesis of collagen?

A

collagen glycosyltransferases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the major structural component of ECM?

A

collagen (25% total protein mass in mammals, 90% of material in bone/dentin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Why is hydrogen bonding so important in collagen?

A

the bonds stabilize the triple helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the 5 classified groups of collagen in the gingiva?

A
  • dentinogingival
  • alveogingival
  • circumferential
  • periosteal
  • transseptal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Type II OI can occur as an autosomal dominant mutation, but occurs mainly as ___.

A

a spontaneous mutation due to perinatal lethality or parent mosaicism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are the driving forces of the tissue and ECM?

A

the functional requirements of it, such as available matrix components and metabolic costs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Which residue is especially affected in Type II OI?

A

glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

____ encode for vast ECM components and can be used to assemble ideal ECM for a given tissue.

A

Genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Bone and teeth have ____ ECM.

A

hard, calcified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the roles of extracellular matrix in embryonic development?

A

cell adhesion
cell migration
tissue morphogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Glycine has the ___ side chain of the gly-X-Y complex of collagen.

A

LEAST bulky

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Mutations of what two Type I collagen genes are associated with osteogenesis imperfecta?

A

COL1A1 and COL1A2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the functions of the collagen fibers in the gingiva?

A
  • anchoring gingival tissue to tooth/alveolar bone

- resisting masticatory forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Where does nucleation of the procollagen triple helix occur?

A

at the C-propeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Which type(s) of dentinogenesis imperfecta is due to mutations in DSPP?

A

Shields Type II and Shields Type II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Mutations in Type II collagen can cause ____.

A

chondrodysplasias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What cells and structures are found in the stroma?

A 
fibroblasts
collagen fibers
elastic fibers
capillaries
macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Classical osteogenesis imperfecta is due to ___ or ___ abnormalities of Type I collagen. What does this mean?

A

quantitative; qualitative; the amount or the quality of type I collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

___ can be caused by mutations in the Type I collagen genes OR in genes encoding proteins involved in post-transcriptional modifications or regulation of collagen biosynthesis.

A

Osteogenesis imperfecta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is a D-period?

A

pair of a lightly-stained and a darkly-stained region of fibrillar collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What accounts for the less-rigid structure and greater flexibility of non-fibrillar collagens?

A

the shorter triple-helical domains interrupted by non-collagenous sequences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Chondrodysplasias are linked to mutations in what type of collagen?

A

Type II (cartilage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the major collagens in the non-fibrillar collagens?

A

Type IV, VI, VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Which type of EDS is characterized by joint hypermobility?

A

hypermobility EDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Which types of collagen are found in the enamel organic matrix region at the DEJ?

A

Type IV and Type VII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Mutations in any of what complex can lead to many different types of autosomal recessive OI’s independent of mutated Type I collagen?

A

the prolyl hydroxylation complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What underlies all epithelial cell layers?

A

basal lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Which type of OI has a severity level between Types I and III?

A

Type IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What accounts for the characteristic banding of fibrillar collagens?

A

quarter-staggered array

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Which types of EDS are caused by mutations in collagen genes?

A

classical
hypermobility
vascular
arthrochalasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Which types of OI are actually considered to be autosomal recessive?

A

Types VI-XVI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What are some ways that collagen function can be mutated and disrupted?

A
  • collagen genes themselves
  • enzymes involved in post-translational modification
  • developing an antibody against collagen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is collagen’s quaternary structure?

A

3 helical a-chains stabilized by hydrogen bonds between glycine and residue X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

____ collagens are large collagenous domains of about 1000 amino acids.

A

Fibrillar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Type __ collagen is found in cartilage and in eyes. It helps to regulate spacing and diameter of Type II collagen fibrils.

A

XI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

The ___ protein modifies collagen expression in moderate to progressively-deforming OI.

A

WNT1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Where does collagen biosynthesis occur?

A

in compartments of the ER and Golgi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Why is the basal lamina important?

A

its filtering (glomerulus) and anchoring/attachment capabilities + cell polarity, cell metabolism, cell survival and proliferation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Which protein is involved in the lysyl hydroxylation of collagen and leads to moderate to severe OI?

A

PLOD2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

A collagen fibril’s strength can be attributed to ____.

A

collagen cross-linking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What kind of material can ECM be viewed as? Why?

A

composite material; because many different components with different mechanical properties combine and organize to create a tissue with optimal properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Hydroxylation, glycosylation, and intrachain disulfide bonding are all ____ modifications that occur in the beginning stages of collagen biosynthesis.

A

post-translational

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What component of ECM accounts for the elasticity or resilience?

A

elastin (elastic fibers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Which type of OI has mutations in COL1A1, but rarely in COL1A2?

A

Type IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is the principal type of collagen found in cartilage matrix?

A

Type II collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Collagen arranged in orthogonal lattices are found in ___.

A

the corneas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What are the resulting phenotypes in a mutation of any one of the different proteins associated with the same pathway?

A

the phenotypes for each would be very similar, even if the protein mutated was different

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

From what developmental lineage are stromal cells derived?

A

mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What types of collagen mutations are linked to Ehlers Danlos syndrome?

A
  • mutations in fibrillar collagens Types III and V

- mutations in enzymes involved in post-translational modifications of collagens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Type I collagen is a heterotrimer of __ a1(I) chains and __ a2(I) chains encoded by two separate genes.

A

2; 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What types of collagen are heterotrimers?

A

Type I and Type VI

96
Q

Which type of OI results from mutations in the COL1A1 and COL1A2 that produce abnormal pro-alpha collagen chains that become incorporated into collagen trimers and disrupt the triple helical structure?

A

Type II OI

97
Q

Which type of OI is characterized by short statuure, spinal curvature, severe bone deformities, and blue sclera?

A

Type III OI

98
Q

Which proteins facilitate prolyl hydroxylation in collagen biosynthesis?

A

CRTAP
LEPRE
PPIB

99
Q

What type of deficiency results when normal trimers are formed, but only half of the normal collagen is produced?

A

quantitative deficiency; In Type I OI, since only one allele is active and producing, only half of the normal collagen is produced

100
Q

Mutations in prolyl and lysyl hydroxylases, FKBP10, collagen glycosyltransferases, PDI, or Hsp47 could all potentially lead to what condition?

A

autosomal recessive OI, or Types V-XVI (types of OI with no mutations in the Type I collagen genes)

101
Q

___ fibers hold the attached gingiva against the bone.

A

Periosteal

102
Q

What component of ECM accounts for resilience or resistance to compression?

A

proteoglycans

103
Q

Which two non-fibrillar collagens have an important role in the basement membrane?

A

Type IV and Type VI

104
Q

What makes up the majority of bone, cartilage, and teeth (specialized connective tissues)?

A

extracellular matrix

105
Q

What confers the twist in the collagen helices that prevents other secondary structures from forming?

A

proline

106
Q

What protein is responsible for cleaving off the C-propeptides on procollagen?

A

BMP-1 or tolloid proteinases

107
Q

What do all collagen molecules contain at least one of?

A

one triple-helical region called a collagenous domain

108
Q

Fibronectin, vitronectin, and laminin are ____ proteins.

A

adhesive

109
Q

Type I collagen fibrils, oxytalan fibers composed of fibrillin, and Sharpey’s fibers are all components of the ____.

A

periodontal ligament (PDL)

110
Q

Corneas have ___ ECM.

A

optically transparent

111
Q

What makes up the complex that carries out collagen prolyl hydroxylation?

A

CRTAP
Cyclophilin B (PPIB)
Prolyl-3-hydroxylase 1 (LEPRE1)

112
Q

____ is a type of EDS caused by a mutation in PLOD1.

A

Kyphoscoliosis

113
Q

___ collagen is a homotrimer encoded by the COL2A1 gene.

A

Type II

114
Q

What does a CRTAP null mutation result in?

A

lethal form of OI (Type II)

115
Q

What types of collagen are homotrimers?

A

Type II

116
Q

Patients with epidermolysis bullosa (EB) have mutations in what type of collagen?

A

7 (VII)

117
Q

What are the amino acids found in collagen fibers?

A

glycine, proline, hydroxyproline, alanine, serine, lysine, hydroxylysine

118
Q

What are some symptoms of scurvy?

A 
lethargy
bleeding gums
bone pain
fragile vessels
loosening of teeth
119
Q

What structures contain specialized mineralized connective tissues?

A

teeth and bone

120
Q

A wickerwork pattern of collagen would be found in what tissue? Why?

A

skin; resists tensile stress in multiple directions

121
Q

What are the collagen fibrils crosslinked by after their formation? Why is this important?

A

lysines of adjacent molecules; greatly increases tensile strength

122
Q

Which type of EDS is characterized by skin hyper-extensibility?

A

classical EDS

123
Q

At what stage does collagen crosslinking by lysyl oxidases occur?

A

after the formation of tropocollagen

124
Q

____ are trimeric molecules consisting of 3 identical (homotrimeric) or non-identical (heterotrimeric) polypeptide chains (alpha-chains).

A

Collagens

125
Q

What is the only calcified tissue that does not contain abundant collagen?

A

enamel

126
Q

What dictates the composition of extracellular matrix in each tissue?

A

the biochemical and functional requirements of the tissue

127
Q

What are the mechanical properties of a tissue?

A

amount and type of ECM macromolecules present and their organization

128
Q

The ___ and ___ have a stromal matrix containing collagen.

A

gingiva; periodontium

129
Q

____ OI is usually autosomal dominant, but can sometimes be autosomal recessive.

A

Type III

130
Q

Is osteogenesis imperfecta primarily autosomal dominant or autosomal recessive?

A

autosomal dominant

131
Q

Which type of dentinogenesis imperfecta occurs in a racial segregate in Maryland and is due to mutations in DSPP?

A

Shields Type III

132
Q

Type __ collagen is associated with Type I and may regulate the assembly of heterotypic fibers.

A

V

133
Q

What is the primary component of the glycoproteins in the basal lamina?

A

laminin

134
Q

Mutations in COL6A are associated with what disease?

A

Bethlem myopathy

135
Q

What chaperone protein binds to the disulfide-bonded collagen trimers and helps complete the formation of the triple helix in collagen biosynthesis?

A

Hsp47

136
Q

Why are proline and hydroxyproline located on the outside of the collagen helices?

A

because they have the bulkiest side chains and cannot fit in the middle

137
Q

What, typically, are X and Y in the collagenous domain of gly-X-Y?

A 
X = proline
Y = hydroxyproline
138
Q

In gene nomenclature, where is the collagen type noted?

COL2A1

A

at the 2

139
Q

____ dentinogenesis imperfecta (III, IV) is not associated with OI and is due to mutations in DSPP.

A

Shields Type II

140
Q

What are all of the fibrillar collagens (major and minor)?

A

I, II, III, V, XI, XXIV, XXVII

141
Q

What does PDI do in the biosynthesis of collagen?

A

facilitates the bonding of cysteine residues at the nucleation point

142
Q

A mutation in COL18 can lead to ____ syndrome, which can cause retinal detachment.

A

Knobloch

143
Q

What region of the oral cavity is composed of collagen fibers in a connective tissue or stromal matrix?

A

lamina propria beneath the oral epithelium

144
Q

____ OI is where abnormal collagen molecules are incorporated together with normal collagen molecules, but few or no normal collagen trimers are produced.

A

Type II

145
Q

What assists in the correct trimerization and folding of collagen?

A

many enzymes and molecular chaperones

146
Q

Why does scurvy lead to major issues with collagen integrity?

A

because scurvy occurs when there is a vitamin C deficiency; vitamin C is a critical cofactor in the hydroxylation step of collagen biosynthesis; no vitamin C = no cofactor = collagen biosynthesis shuts down

147
Q

What facilitates the crosslinking of lysines between collagen fibrils?

A

5 lysyl oxidases

148
Q

What does Type VII collagen form that interacts with the Type I collagen in the stroma and Type IV collagen and laminin in the basement membrane?

A

anchoring fibrils

149
Q

What reduces the tensile strength of fibrils and increases tissue fragility?

A

inhibition of crosslinking

150
Q

Which tissue has an extracellular matrix that is more abundant than the cells themselves?

A

connective tissue

151
Q

What type of non-fibrillar collagen is highly expressed in the hypertrophic cartilage of growth plates?

A

Type IX

152
Q

Are COL1A1 and COL1A2 the only genes that can cause OI?

A

NO - up to 15 genes have been known to cause OI

153
Q

What would a functional null allele do to the COL1A1 and COL12A genes?

A

no protein would be produced from ONE of the alleles

154
Q

Is the banding in fibrillar collagen lightly or darkly stained in the regions where there are gaps between the collagen fibers?

A

dark

155
Q

Type __ fibers surround enamel rods and may play a role in attaching enamel to underlying dentin.

A

VII

156
Q

___ form a hydrated gel in which fibrous proteins embed and resist compression and allow diffusion of nutrients.

A

GAGs

157
Q

Which type of OI is caused only by a mutation in COL1A1?

A

Type I

158
Q

The proteolytic processing of procollagen occurs before the formation of tropocollagen and is a _____ modification.

A

post-translational

159
Q

Which type of EDS leads to the fragility and rupture of arteries?

A

vascular EDS

160
Q

In specialized tissues, what is the extracellular matrix secreted by?

A

fibroblast-related cells (osteoblasts, chondrocytes, odontoblasts)

161
Q

What are stroma?

A

cells embedded in matrix

162
Q

___ and ___ are proteins that are both involved in the folding processes of collagen.

A

SERPINH1; FKBP10

163
Q

____ fibers are calcified into cementum/bone on one end and are free at the other end to hold the free gingiva against the tooth.

A

Dentinogingival/Alveogingival

164
Q

What are the 6 genes that encode Type IV collagen chains?

A

COL4A1 - COL4A6

165
Q

___ different collagens have been identified. They are encoded by up to how many different genes?

A

28; 42

166
Q

___ dentinogenesis imperfecta occurs in families with OI due to mutations in COL1A1 or COL1A2.

A

Type I

167
Q

What are the 3 major fibrillar collagens?

A

I, II, and III

168
Q

Fibrillar collagens assemble into polymeric, rod-like structures called ____.

A

collagen fibrils

169
Q

Which fibers of the periodontal; ligament are located within the furcation of the roots?

A

interradicular fibers

170
Q

What type of collagen is important in anchoring the epidermis to the underlying dermis?

A

Type VII

171
Q

What does a collagenous domain require the presence of?

A

presence of glycine every 3rd amino acid

172
Q

___ is a type of EDS caused by a mutation in ADAMTS2.

A

Dermatosparaxis

173
Q

Which fibers of the periodontal ligament are found at the crest of the periodontal ligament, nearest the neck of the tooth?

A

alveolar crest fibers

174
Q

What categories are the collagens divided into?

A

fibrillar and non-fibrillar

175
Q

What synthesizes the basal lamina?

A

the cells that rest on it

176
Q

Which protein in collagen biosynthesis helps with the folding of the triple helix?

A

SERPINH1 (Hsp47)

177
Q

What are collagen molecules characterized by structurally?

A

long, stiff triple-stranded helical structure with 3 alpha-chains wound around each other in a superhelix

178
Q

Which fibers of the periodontal ligament are located at the apex of the root?

A

periapical fibers

179
Q

Which types of EDS are caused by mutations in genes involved in the collagen biosynthetic pathway?

A

kyphoscoliosis

dermatosparaxis

180
Q

What does collagen in the PDL attach to?

A

attaches cementum layer of tooth root to the alveolar bone

181
Q

What component of ECM accounts for the controlled elasticity of a tissue?

A

fibrillin-1 (microfibrils)

182
Q

In ____ collagens, the triple-helical domains are shorter and interrupted by non-collagenous sequences.

A

non-fibrillar

183
Q

Collagen, elastin, fibrillin, fibronectin, vitronectin, and laminin are all ____ proteins.

A

fibrous

184
Q

Which type of collagen is needed for adhering the basal lamina to the underlying stroma/epithelial tissues?

A

Type VII (7)

185
Q

Why are many diseases with mutations in extracellular matrix proteins inherited in a dominant fashion?

A

because many of these ECM proteins form polymeric structures, so just one messed up fibril can affect the entire polymeric structure

186
Q

What two enzymes must act in order for collagen to be converted into tropocollagen for fibril formation to occur?

A

ADAMTS2,3,14 and BMP-1/tolloid proteinases

187
Q

How many genes encode type II collagen?

A

1 because it is a homotrimer

188
Q

___ fibers encircle the tooth.

A

Circumferential

189
Q

Which protein in collagen biosynthesis is responsible for N-propeptide cleavage in collagen biosynthesis?

A

ADAMTS2

190
Q

What is the tertiary structure of collagen?

A

there is NOT one

191
Q

Which condition is associated with abnormal collagen biosynthesis due to a nutritional deficiency in vitamin C?

A

scurvy

192
Q

Which type of non-fibrillar collagen is a key component of anchoring fibrils that attach epithelia to the underlying connective tissue?

A

Type VIII

193
Q

What is the Type IV alpha-3 chain important in?

A

glomerular basement membrane

194
Q

Tendons have ECM that ____.

A

has a rope-like organization of collagen to give tensile strength in one direction

195
Q

What is the principal type of collagen found in the ECM of tendons, bones, ligaments, the PDL, dentin, fascia, and skin?

A

Type I collagen

196
Q

Collagens arranged in concentric weaves would be found in ___.

A

bone

197
Q

What component of ECM accounts for the strength, hardness, and brittleness of the tissue?

A

mineral (hydroxyapatite)

198
Q

What type of substance contains collagen embedded in polysaccharide ground substance of hyaluronan and proteoglycans/glycosaminoglycans?

A

stromal matrix

199
Q

The hydroxylation of what two amino acid bases in collagen biosynthesis occurs in humans but is rare in other animal proteins?

A

prolines and lysines

200
Q

What is the use of bisphosphonates associated with?

A

potential osteonecrosis of the jaw

201
Q

Which protein in collagen biosynthesis assists with protein folding?

A

FKBP10

202
Q

What happens when hydroxylation is stalled in collagen biosynthesis due to vitamin C?

A

unfolded procollagen is retained in the ER and degraded and cannot renew the connective tissue matrix AKA deficient collagen assembly

203
Q

What are the long polysaccharides called that consist of repeating disaccharide units often covalently linked to proteins in the form of proteoglycans?

A

glycosaminoglycans (GAGs)

204
Q

What is the purpose of oxytalan fibers?

A

the fibrillin within them allow for elasticity for tooth movement

205
Q

Which protein of the prolyl hydroxlation complex is required for hydroxylation in collagen biosynthesis and mutations of it may cause recessive OI?

A

CRTAP

206
Q

What structures contain proteoglycan-rich specialized connective tissue?

A

cartilage

207
Q

What are the functions of extracellular matrix in bone?

A
  • support and locomotion
  • calcium homeostasis
  • protect brain, organs
208
Q

Collagens undergo extensive post-translational modifications in the ___ prior to the triple helix formation.

A

ER

209
Q

What is the most severe type of chondroplasia?

A

achondrogenesis type II or hypochondrogenesis

210
Q

What are the functions of extracellular matrix in teeth?

A
  • provides strength/structure to tooth

- resists shear and compression forces

211
Q

Which fibers of the periodontal ligament are horizontally positioned in the middle of the root?

A

horizontal fibers

212
Q

Which type of OI is the most severe (perinatal lethal)?

A

Type II

213
Q

What do prolyl hydroxylases and lysyl hydroxylases do?

A

hydroxylates selected prolines and lysines for the synthesis of procollagens

214
Q

___ fibers run between the teeth.

A

Transseptal

215
Q

What are utilized in tissues according to their desired properties, such as regulation of assembly proteins, binding of growth factors and regulation of mineralization?

A

other ECM components

216
Q

What is the secondary structure of collagen?

A

extended left-handed helix

217
Q

What are some examples of mutations that can occur that result in Type I OI?

A
  • allelic deletion
  • promoter/enhancer mutations
  • splicing mutations
  • premature termination
218
Q

Are COL1A1 and COL1A2 associated with all 4 types of OI?

A

YES

219
Q

What component of the prolyl hydroxylation complex actually hydroxylates the collagen alpha chain?

A

prolyl-3-hydroxylase (LEPRE1)

220
Q

____ is a hereditary disease of dentin where patients present with brown teeth that wear easily, bulbous crowns, narrow roots, small pulp chambers, and often experience splitting of the enamel.

A

Dentiogenesis imperfecta

221
Q

What is the most abundant amino acid found in collagen fibers?

A

glycine

222
Q

Prolyl hydroxylases and lysyl hydroxylase require what as a cofactor?

A

vitamin C

223
Q

What are the roles of extracellular matrix in the regulation of cell function?

A

signaling
growth
differentiation

224
Q

What are the characteristics of Ehlers Danlos syndrome?

A
  • fragility of soft connective tissues
  • issues with skin, joints, ligaments
  • joint hyperlaxity
  • reduced bone mass (osteopenia)
225
Q

What type of fibrous proteins provide tensile strength and elasticity?

A

structural (collagen, elastin, fibrillin)

226
Q

Type I OI is characterized as having ____ type I collagen.

A

reduced amounts of NORMAL

227
Q

Collagen prolyl hydroxylation is carried out by a ____.

A

complex

228
Q

What must the ECM of a tissue be able to respond to?

A

changes in the mechanical requirements (functional adaptation)

229
Q

If a patient with OI presented with normal stature, blue sclera of the eyes, and had a history of bone fractures before the onset of puberty, what would you classify their OI as?

A

Type I

230
Q

Patients with Ehlers Danlos syndrome can be particularly prone to life-threatening ___.

A

rupture of blood vessels

231
Q

What type of osteogenesis imperfecta is the most common and the mildest?

A

Type I

232
Q

____ contains abundant collage fibers to attach gingiva to the tooth and alveolar bone.

A

Gingiva

233
Q

How does achondrogenesis type II occur? What is the mutation?

A

replacement of a glycine by a much bulkier amino acid

234
Q

What type of collagen tethers the underlying connective tissue?

A

type VII anchoring fibrils

235
Q

In patients with dentinogenesis imperfecta, what are some patient care precautions that need to be taken into consideration?

A
  • tooth may lose feeling
  • teeth can wear all the way down to gingiva
  • need meticulous oral hygiene
  • extra support of jaw for tooth extractions

Biochemistry Final Exam (8 decks)

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