Review Power Point Flashcards
1
Q
What 3 things make up ground substance?
A
Glycoproteins
Glycoseaminoglycans
Proteoglycans
2
Q
Ground substance participates in binding cells to fibers of what?
A
Fibers of connective tissues
3
Q
What is a glycoprotein?
A
A protein with 1 or more attached sugars
4
Q
GAGs are a family of what?
A
Heteropolysacharides
5
Q
What are 2 important characteristics of GAGs?
A
Very hydrated
Very negative
6
Q
What makes up proteoglycans?
A
A protein core with many GAG side chains
Bottle brush
7
Q
What makes and secretes the large majority of extracellular matrix?
A
Neighboring cells
8
Q
What is the most common cell of connective tissue?
A
Fibroblasts
9
Q
What cells secrete dentin?
A
Odontoblasts
10
Q
What cells secrete enamel?
A
Ameloblasts
11
Q
What is the structure of tropocollagen?
A
3 helical strands
12
Q
How do tropocollagen fibrils arrange themselves?
A
In a staggered array of parallel bundles
13
Q
What causes striations in tropocollagen?
A
The alignment of every 4th molecule
14
Q
Tropocollagen crosslinks via what?
A
Lysinonorleucine
15
Q
Production of lysinornorleucine requires which enzyme?
A
Lysyl amino oxidase
16
Q
What cofactor is needed for lysyl amino oxidase?
A
Vitamin B6 (pyridoxine)
17
Q
What types of collagens are found in interstitial connective tissue?
A
Types I, II, III, V, XI
18
Q
What is the most abundant collagen type
A
Type I
19
Q
Most connective tissues have which collagen type?
A
Type I
20
Q
What are some examples of tissues containing type I collagen?
A
Bone Tendon Skin Dentin Ligament Fascia Arteries Uterus
21
Q
Type II collagen is a component of what type of cartilage?
A
Hyaline cartilage
22
Q
Where is the 1 optometry correlation of type II collagen found?
A
In vitreous humor
23
Q
Reticular fibers are made up of which collagen type?
A
Type III
24
Q
Where are 3 places that type III collagen is found?
A
Skin
Arteries
Uterus
25
What is the predominant collagen type in periodontal ligament?
Type III collagen
26
T/F Type III collagen is often found in bone.
False
27
Which collagen type is the most abundant structural component of basement membranes?
Type IV
28
The lens has which collagen type?
Type IV
29
What makes type VIII collagen?
Endothelial cells
30
What makes type X collagen? When does this occur?
Chondrocytes
| During endochondral ossification
31
Which collagen types are multiplexins?
Types XV and XVIII
32
Where are multiplexins found?
In basement membranes
33
Multiplexins have multiple triple helix domains and ___.
Interruptions
34
What is the precursor to tropocollagen?
Procollagen
35
What are the 6 steps of converting preprocollagen to procollagen?
1. Signal peptide cleavage
2. Registration peptides
3. Hydroxylate proline and lysine
4. Attach sugars to hydroxyproline and hydroxylysine
5. Forme triple helix
6. Package into vesicles
36
What are the 3 steps to convert procollagen to tropocollagen?
1. Registration peptides cleaved off; forms insoluble tropocollagen
2. Aggregation of tropocollagen forms fibrils
3. Fibrils cross link
37
Which amino acid is involved in making desmosine cross links of elastin>
Lysine
38
The fibronectin network is secreted as what?
A dimer of 2 large monomers
39
Where are the 2 large monomers of the fibronectin network connected near?
C-terminals by disulfide bonds
40
What stabilizes the fibronectin network?
Transglutamase cross-linking
41
Unlike collagen, the fibronectin network assembly requires ___.
Cells
42
What does the fibronectin network do?
Helps organize extracellular matrix and mediate cell adhesion
43
Elastic fibers consist of an ___ component comprised of elastin.
Amorphous
44
Where are elastic fibers found?
Smooth muscle
Arteries
Elastic connective tissue
45
What are the triple stranded helices of elastin called?
Tropoelastin
46
Elastin is rich in which amino acids?
Glycine
Alanine
Lysine
47
Elastin fibers crosslink via what?
Desmosines
48
What is strange about the elastin helix?
It is not a true alpha helix
49
What makes up elastic fibers?
Fibrillins and other small proteins
50
Fibrillins are a family of large what?
Large glycoproteins consisting of EGF-like motifs
51
Where are fibrillins found?
Arterial linings
| Heart valves
52
What "coats" elastin fibers?
Fibrillins
53
Elastin and fibrillins are ubiquitous where?
In connective tissues
54
What fibers are made first in fibrillin developments?
Oxytalan fibers
55
Why is elastin insoluble?
Extensive cross-linking
56
Laminins will bind to which ECM components?
Heparin
Type IV Collagen
Nidogen/entactin
57
Complexes of laminins and ___ provide structural organization to basement membranes?
Heparan sulphate, as well as "other molecules"
58
What 2 functions do laminins carry out in basement membranes?
Structural organization
| Binding site for cells
59
What is the shape of nidogen/enactin?
Dumbell shaped
60
What is found on the ends of nidogen/enactin?
A laminin/collagen IV building domain on one end, and a self aggregating domain on the other
61
What separates the two ends of nidogen/enactin?
A rod-like connecting domain
62
What does nidogen/enactin do?
Dimerizes, then cross links laminin and type IV collagen
63
Nidogen/enactin is a 50 KD glycoprotein found where?
In all basement membranes
64
Fibulins contain __ EGF-like repeats?
9
65
What do fibulins bind to?
```
Laminins
Nidogen
Fibrinogen
Collagen IV
Other fibulins
```
66
What do fibulins do?
Thought to link cells to basement membranes
67
Fibulins are which type of protein?
Glycoprotein
68
In basement membranes, what forms an extensive, partially cross-linked network?
Type IV collagen
69
What do laminin 1 and nidogen do in the structure of basement membrane?
Form a second extensive network
70
What links the 2 major networks of basement membrane?
Nidogen binding to collagen IV
71
What do proteoglycans do in the basement membrane structure?
Intermix with the networks
72
What do fibulins bind in the basement membrane?
Nidogen
Laminin 5
Fibronectin
Collagen IV
73
In the structure of basement membrane, fibronectin binds to what?
All collagen
74
There is a log of ___-___ in the basement membrane.
Cross-linking
75
How many amino acids are in osteocalcin?
50
76
3 of the amino acids in osteocalcin are what?
Gamma-carboxyglutamate (Gla)
77
The 3 gamma-carboxyglutamates in osteocalcin are formed post-translationally in what type of reaction?
Vitamin K dependent reaction
78
What does osteocalcin bind to?
Binds calcium with high affinity
| Adheres to hydroxyapatite crystals
79
Where is osteocalcin found?
Bone
Dentin
Cementum
80
What other role might osteocalcin play?
Regulating crystal growth (negative regulator)
81
What forms nanochains?
Amelogenin
82
What type of protein is amelogenin (fibrous or globular)?
Globular
83
Amelogenin self-assembles into what?
Nanospheres
84
What is the driving force for formation of parallel bundles of apaptite during enamel formation?
The self-assembly of amelogenin into nanochains (regulated crystal growth)
85
What is the hallmark cell of acute inflammation?
Neutrophil
86
What degrades elastin?
Neutrophil elastase
87
Elastase is which type of enzyme?
Serine protease
88
What inactivates elastase?
Alpha-1 antitrypsin
89
What does a deficiency in alpha-1 elastase result in?
Emphysema
90
What are the common symptoms of the group of 10 diseases in Ehlers-Danlos syndrome?
Fragile, hyperextensible skin
| Hypermobile joints
91
Most forms of EDS result from defects in which types of collagen?
Types I, II, and III
92
What is the most sever type of EDS?
Type IV
93
What is the gene mutation associated with type IV EDS?
col3A1 gene
94
How is EDS type IV passed genetically?
Autosomal dominant
95
The overextensible tissues caused by EDS type IV can lead to what?
Arterial rupture (sudden death)
Intestinal perforation
Rupture of uterus
Easily bruised, translucent skin
96
What does the mutation of collagen alpha 1 (III) gene that causes EDS IV actually cause to occur?
Slow synthesis
Defective secretion
Increased susceptibility to degredation
97
Osteogenesis imperfecta is a group of how many diseases?
8
98
What causes osteogenesis imperfecta?
Defective chains assembling to form defective helices, then fibrils and fibers
99
What is the major symptom of EDS types VII A, B, C?
Dislocation of major joints
100
EDS types IVV A and B result from what mutation?
Mutations of collagen alpha 1 (I) or alpha 2 (I) gene
101
A mutation in the collagen alpha 1 (I) or alpha 2 (I) gene eliminates what?
The cleavage site for collagen N-protease
102
A lack of the cleavage site for collagen N-protease will cause what?
Incompletely processed collagens to assemble and form defective fibrils
103
How is EDS VII C passed genetically?
Autosomal recessive
104
EDS VII C (dermatosparaxis) results from a deficiency in what?
Collagen N-protease
105
Blue sclera results from ___ ___ caused by what?
Osteogenesis imperfecta
| Defective type I collagen
106
What is the most common type of osteogenesis imperfecta?
Type I
107
What are some symptoms of type I osteogenesis imperfecta?
Easily fractured bones
Loose joints
Blue sclera
108
Which subtype of type I osteogenesis imperfecta results in dentinogenesis imperfecta?
Type IB
109
What is the problem in osteogenesis imperfecta type I?
Normal collagen, but not enough of it
110
What type of metabolism does cardiac muscle undergo?
Totally areobic
111
Cardiac muscle oxidizes what 2 things?
Glucose
| Ketone bodies
112
How does cardiac muscle store energy?
As phosphocreatine
113
After a heart attack, which enzyme spikes the highest and fastest?
Troponin
114
What are the 3 enzymes to look for after a heart attack?
Lactate dehydrogenase
Troponin
Creatine kinase
115
After a heart attack, which enzyme takes the longest to spike?
Lactate dehydrogenase
116
What forms the globular "heads" of myosin?
Amino terminus
117
In myosin, 2 heavy chains coil from where?
Carboxy terminus
118
In myosin, light chains are associated with which region?
Head region
119
In myosin, cleavage with trypsin and papain result in what?
Heavy and light meromyosin
120
Which is the important calcium sensing troponin?
C troponin
121
What does I troponin do?
Inhibits
122
When a sarcomere contracts, which band gets smaller? Which band stays stable?
I band shortens
| A band doesn't change
123
What are the boundaries of a sarcomere?
Z disk to Z disk
