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103 Cards in this Set
- Front
- Back
60. Which of the following amino acids can be used as a marker in estimating the amount of collagen in a tissue sample?
A. Aspartate B. Hydroxyproline C. Lysine D. Serine E. Threonine |
Hydroxyproline
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61. Which of the following statements concerning collagen is INCORRECT?
A. Collagen has a trihelical structure B. The molecular weight of collagen is above 100,000 C. Hydroxyproline is not incorporated into the molecule by tRNA D. Under-hydroxylated collagen is fully functional E. Collagenases can destroy collagen |
Under-hydroxylated collagen is fully functional
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62. Hydroxylation of proline and lysine during collagen biosynthesis occurs
A. after translation B. in the mitochondrial matrix C. before formation of their respective tRNA's D. while proline and lysine are bound to the P site on the ribosome E. outside the cell |
after translation
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63. Lysyl oxidase forms intermolecular crosslinks between both collagen and elastin monomers. This extracellular reaction results in the formation of
A. Hydroxylysine B. Lysine C. Hydroxyproline D. Allysine E. Elastin |
Allysine
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64. Glycine is found at every third residue in the collagen triple helix. Glycine is important in the structure of collagen because
A. its lack of rotational freedom about the carbon forces the chain into a helical conformation B. its side chain is small and allows the α-chains to fit closely together C. it has many tRNA's and can be made rapidly D. it cannot be hydroxylated E. All of the above are correct |
its side chain is small and allows the α-chains to fit closely together
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65. Elastin provides tissue with
A. tensile strength B. multiple binding sites for matrix molecules C. resiliency D. sites for water storage E. binding sites for heme breakdown products |
resiliency
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66. Mucopolysaccharides are important in connective tissue because they provide
A. Viscosity B. Hydrogen ion buffering C. Calcium buffering D. Calcification precipitation points E. A hydrophobic environment |
Viscosity
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67. Which of the following is NOT a component of connective tissue?
A. Elastin B. Collagen C. Keratin D. Chitin E. Laminin |
Chitin
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68. Keratin sulfate would be found in highest concentration in
A. Bile B. Blood C. Cartilage D. Gastric secretions E. Urine |
Cartilage
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69. Every third amino acid in collagen is glycine. The abundance of glycine is important in collagen because
A. its small R group allows the alpha chains to fit tightly together B. the charge on the glycine R group attracts water C. the R group on glycine serves as a condensation point for hydroxyapatite D. glycine is the most abundant of the amino acids and therefore readily available for collagen synthesis E. glycine reduces rotational freedom of the alpha helix |
its small R group allows the alpha chains to fit tightly together
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70. Which of the following is the R group that would be found most often in collagen?
A. -H B. -CH3 C. -CH2-CH2OH D. -COOH E. -CH2-COOH |
-H
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71. Which of the following are needed for hydroxylysine and hydroxylproline synthesis?
A) Ascorbate B) α-ketoglutarate C) Vitamin B6 D) Copper E) Iron A. A, C and E B. B and D C. A, B and E D. C, D and E E. A, B and D |
A, B and E
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72. Collagen crosslinks result when which of the following structures is formed?
A. Hydroxylysine B. Allysine C. Lysinonorleucine D. Hydroxyproline E. Elastin |
Allysine
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73. For collagen to be completely hydroxylated which of the following post-translational modifications must first occur?
A. Lysyl oxidation B. Lysyl hydroxylation C. Lysyl reduction D. Proline oxidation E. Glycine carboxylation |
Lysyl hydroxylation
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74. Which of the following would be characterized by the presence of primarily Type IV collagen?
A. Bone B. Cementum C. Dentin D. Basal Lamina E. Cartilage |
Basal Lamina
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75. Which of the following is NOT a component of proteoglycans?
A. Chondroitin sulfate B. Dermatan sulfate C. Heparan sulfate D. Keratan sulfate E. All of the above are components of proteoglycans |
All of the above are components of proteoglycans
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76. Core proteins attach to hyaluronate by
A. Covalent bonds B. Hydrogen bonds C. Van der Waals bonds D. Covalent bonds to a link protein E. Non-covalent bonds to a link protein |
Non-covalent bonds to a link protein
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77. Which of the following glycosaminoglycans is typically found in the basal lamina?
A. Keratan sulfate B. Dermatan sulfate C. Heparan sulfate D. Chondroitin sulfate E. Dextran sulfate |
Heparan sulfate
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78. Laminin consists of how many subunits?
A. 1 B. 2 C. 3 D. 4 E. 5 |
3
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79. Which of the following does NOT have a binding domain on fibronectin?
A. Collagen B. Fibrin C. Heparan sulfate D. Integrin E. Proteoglycan core protein |
Proteoglycan core protein
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80. Which of the following is NOT required for elastin crosslinking to occur?
A. Copper B. Vitamin B6 C. Oxygen D. α-ketoglutarate E. All of the above are required |
α-ketoglutarate
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81. Which of the following explains elastin's resiliency?
A. Loose peptide bonds B. Hydrogen bonding between tropoelastin elements C. Exposure of hydrophobic R groups to water when elastin is stretched D. Electrostatic repulsion of R groups when elastin is stretched E. Cystine formation when elastin is stretched |
Exposure of hydrophobic R groups to water when elastin is stretched
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82. Integrin is comprised of ____ subunits
A. 1 B. 2 C. 3 D. 4 E. 5 |
2
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83. Which of the following would be the best choice for use in radiolabeling experiments designed to study the rate of collagen synthesis?
A. Cysteine B. Proline C. Glutamate D. Hydroxylysine E. Leucine |
Proline
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84. Which of the following molecules would be expected at higher levels in collagen than in other biomolecules?
A. Hydroxyproline B. Tyrosine C. Glycine D. Acetate E. Sulfate |
Hydroxyproline
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85. Which of the following is a fibrous protein component of the extracellular matrix?
A. Selectin B. Laminin C. Keratin D. Fibronectin E. Integrin |
Keratin
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86. Bone is characterized by the presence of which form of collagen?
A. Gel B. Bundle C. Stacked D. Angled bundle E. Circular |
Angled bundle
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87. Which of the following is characterized by high levels of hydroxyproline?
A. Collagen B. Elastin C. Fibronectin D. Proteoglycan E. Glycosaminoglycan |
Collagen
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88. Which of the following statements about collagen synthesis is INCORRECT?
A. Messenger RNA encodes for α1 or α2 chains B. Post-translational processing requires lysylhydroxylase C. The triple helix structure is assembled in the Golgi apparatus D. Cross linking between monomers requires lysyloxidase E. All of the above are correct. |
The triple helix structure is assembled in the Golgi apparatus
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89. In which tissue is elastin apt to be most important for function?
A. Bone B. Cornea C. Skin D. Lung E. Intervertebral discs |
Lung
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90. Desmosine
A. Is the most common amino acid in fibronectin B. Is the linkage point between 4 elastin monomers C. Results from the covalent joining of alanine residues D. Is produced by the action of α1- antitrypsin E. Provides the tensile strength that characterizes elastin |
Is the linkage point between 4 elastin monomers
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91. Which of the following is rich in cysteine and found in hair and nails?
A. Collagen B. Keratin C. Laminin D. Proteoglycan E. Integrin |
Keratin
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92. Fibronectin
A. Can bind to collagen B. Can bind to proteoglycans C. Can bind to cell surface receptors D. Exists as a dimer E. All of the above |
All of the above
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93. Proteoglycans
A. Consist of a core protein and many glycosaminoglycans B. Are covalently bound to hyaluronate in the extracellular matrix C. Are primarily composed of serine and xylose D. Provide tensile strength to tissues E. Are usually very negatively charged |
Are usually very negatively charged
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94. Which of the following would you least likely expect to see in a glycosaminoglycan?
A. Glucuronate B. Glucosamine C. Allysine D. Iduronate E. Galactosamine |
Allysine
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95. Which of the following is the most abundant glycosaminoglycan in the body?
A. Hyaluronate B. Chondroitin sulfate C. Dermatan sulfate D. Heparan sulfate E. Keratan sulfate |
Chondroitin sulfate
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96. An important role of sulfate in many glycosaminoglycans is
A. To form disulfide bridges B. To repel neighboring collagen molecules C. To attract positive ions and water D. To form covalent bonds with cell surface receptors E. All of the above are important functions of sulfate |
To attract positive ions and water
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97. Where are you apt to find high concentrations of proteoglycans?
A. Bone B. Vitreous fluid C. Liver D. Intervertebral discs E. Teeth |
Intervertebral discs
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98. The source of amine groups added to glycosyl units in glycosaminoglycans is
A. Glutamine B. Urea C. Glucosamine D. Ammonia E. Carbamoyl phosphate |
Glutamine
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99. Following analysis of the proteoglycan contents of cartilage, which would you NOT expect to find?
A. Protein B. Sulfate esters C. Heparan sulfate D. Chondroitin sulfate E. Chondroitin |
Heparan sulfate
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100. Hyaluronan
A. consists of alternating glucuronate and N-acetylglucosamine B. contains both glucose and fructose C. is comprised of alternating glucuronate and N-acetylgalactosamine D. contains heparan sulfate E. is an unbranched polymer of N-acetylgalactosamine |
consists of alternating glucuronate and N-acetylglucosamine
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101. Which glycosaminoglycan is NOT synthesized on a protein?
A. Hyaluronan B. Heparin C. Heparan sulfate D. Chondroitin sulfate E. Keratan sulfate |
Hyaluronan
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102. Which of the following does NOT contain glucuronate?
A. Dextran B. Hyaluronan C. Heparin D. Heparan sulfate E. Chondroitin sulfate |
Dextran
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103. A sulfate deficiency would NOT affect the synthesis of
A. Heparin B. Heparan sulfate C. Dermatan sulfate D. Hyaluronan E. Keratan |
Hyaluronan
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104. The most common type of glycosaminoglycan in cartilage is
A. Collagen B. Hyaluronan C. Chondroitin sulfate D. Fibronectin E. Keratan |
Chondroitin sulfate
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105. Glucuronate differs from glucose by the presence of
A. a pyranose ring B. a carboxyl group added at carbon 6 C. an amine group added at carbon 1 D. a sulfate group added at carbon 2 E. a second, sulfated glucose added to carbon 1 |
a carboxyl group added at carbon 6
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106. Aggrecan is
A. stretchable B. compressible C. hydrophobic D. covalently bound to core protein E. cross-linked to collagen by lysyl covalent bonds |
compressible
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107. The proteoglycans on surfaces of basement membranes often serve to
A. repel water B. act as receptors for signal proteins C. regulate filtration across the basement membrane D. separate bone and cartilage E. stimulate elastin synthesis |
regulate filtration across the basement membrane
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108. Which of the following is a fibrous protein component of the extracellular matrix?
A. Selectin B. Laminin C. Keratin D. Fibronectin E. Integrin |
Keratin
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109. Bone is characterized by the presence of which form of collagen?
A. Gel B. Bundle C. Stacked D. Angled bundle E. Circular |
Angled bundle
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110. Which of the following is characterized by high levels of hydroxyproline?
A. Collagen B. Elastin C. Fibronectin D. Proteoglycan E. Glycosaminoglycan |
Collagen
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111. Which of the following statements about collagen synthesis is INCORRECT?
A. Messenger RNA encodes for α1 or α2 chains B. Post-translational processing requires lysylhydroxylase C. The triple helix structure is assembled in the Golgi apparatus D. Cross linking between monomers requires lysyloxidase E. All of the above are correct. |
The triple helix structure is assembled in the Golgi apparatus
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112. In which tissue is elastin apt to be most important for function?
A. Bone B. Cornea C. Skin D. Lung E. Intervertebral discs |
Lung
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113. Desmosine
A. Is the most common amino acid in fibronectin B. Is the linkage point between 4 elastin monomers C. Results from the covalent joining of alanine residues D. Is produced by the action of α1-antitrypsin E. Provides the tensile strength that characterizes elastin |
Is the linkage point between 4 elastin monomers
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114. Which of the following is found in hair and fingernails, and is rich in cysteine?
A. Collagen B. Keratin C. Laminin D. Proteoglycan E. Integrin |
Keratin
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115. Fibronectin
A. Can bind to collagen B. Can bind to proteoglycans C. Can bind to cell surface receptors D. Exists as a dimer E. All of the above |
All of the above
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116. Proteoglycans
A. Consist of a core protein and one or more glycosaminoglycans B. Are covalently bound to hyaluronate in the extracellular matrix C. Are primarily composed of serine and xylose D. Provide tensile strength to tissues E. Are primarily uncharged |
Consist of a core protein and one or more glycosaminoglycans
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117. Which of the following is the most abundant glycosaminoglycan in the body?
A. Hyaluronate B. Chondroitin sulfate C. Dermatan sulfate D. Heparan sulfate E. Keratan sulfate |
Chondroitin sulfate
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118. Glycosaminoglycans are an important component of
A. Glycogen B. Starch C. Cellulose D. Hyaluronidase E. Connective tissue |
Connective tissue
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119. Which two enzymes are particularly important in regulating calcification of hard tissues?
A. Enolase and phosphorylase B. Catalase and alkaline phosphatase C. Carbonic anhydrase and pyrophosphatase D. Alkaline phosphatase and pyrophosphatase E. Alkaline phosphatase and carbonic anhydrase |
Alkaline phosphatase and carbonic anhydrase
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120. Which of the following is INCORRECT regarding collagen?
A. It contains hydroxylysine B. It has a molecular weight of greater than 100,000 C. tRNA is used to add the hydroxyprolines which are abundant in the protein D. Collagenases digest the molecule E. The secondary structure of collagen is trihelical |
tRNA is used to add the hydroxyprolines which are abundant in the protein
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121. Which cell type produces the extracellular matrix found in connective tissue?
A. Mast cells B. Fibroblasts C. Osteoblasts D. Hepatocytes E. Macrophages |
Fibroblasts
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122, Which of the following is a protein which helps cells to adhere to the extracellular matrix?
A. Fibronectin B. Collagen C. Elastin D. Keratin E. Hyaluronan |
Fibronectin
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123. Aggrecan aggregates will provide which of the following functions in extracellular matrix?
A. Elasticity B. Tensile strength in one axis C. Tensile strength in three axes D. Compressibility E. Signal transduction |
Compressibility
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124. Which of the following statements about proteoglycans is INCORRECT?
A. Proteoglycans are glycoproteins B. Glycosaminoglycans are synthesized and then attached to core protein to form a proteoglycan C. Decorin is a proteoglycan D. Proteoglycans can participate in signal transduction E. Proteoglycans cover the surface of cells |
Glycosaminoglycans are synthesized and then attached to core protein to form a proteoglycan
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125. Which form of collagen is found in bone?
A. Gel B. Bundle C. Stacked D. Angled bundle E. Circular |
Angled bundle
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126. Which of the following amino acids is a marker for the presence of collagen?
A. Proline B. Hydroxylysine C. Glycine D. Glutamate E. Glutamine |
Hydroxylysine
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127. A triple helix with hydroxylated R groups and disulfide bonds near the carboxyl terminals would be
A. Preprocollagen B. Pro-α-chain collagen C. Procollagen D. Collagen fibril E. Keratin |
Procollagen
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128. A collagen molecule is correctly described by all of the following statements EXCEPT
A. The most abundant protein in mammals B. Major fibrous element in skin, bone, cartilage and dentin C. Contains 30% lysine D. Cross-linked via modified lysine residues E. Consists of three protein chains |
Contains 30% lysine
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129. All of the following statements about bone tissue are true EXCEPT
A. It replaces mineralized cartilage during bone growth B. It requires both an organic matrix of collagen and a mineral matrix for function C. It is remodeled by osteoblasts removing matrix and osteoclasts forming new bone D. It contains a network of osteocytes with cell-cell contacts E. It can be remodeled in response to sustained mechanical forces |
It is remodeled by osteoblasts removing matrix and osteoclasts forming new bone
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130. Basement membranes
A. Separate bone from cartilage B. Form sheet-like structures with type I collagen C. Often contain the small chondroitin sulfate proteoglycan, decorin, in their structures D. Often contain proteoglycans on their surfaces, which regulate filtration properties E. Prevent entry of nutrients from connective tissues into epithelial tissues |
Often contain proteoglycans on their surfaces, which regulate filtration properties
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131. All of the following statements about elastin are true EXCEPT
A. It contains predominantly amino acids with hydrophobic side chains B. It stores energy when stretched C. It is an important matrix molecule in heart valves and aorta D. It contains mostly hydrophilic amino acid side chains on its surface in the relaxed conformation E. It is readily remodeled and replaced in adult tissues |
It is readily remodeled and replaced in adult tissues
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132. All of the following statements about fibril-forming collagens such as Type I are correct EXCEPT
A. Form trimers with regions of characteristic triple helical structures B. Have glycine residues in every third position in helical regions C. Are synthesized in a precursor form with N– and C-terminal extensions D. Polymerize to form fibrils with rope-like properties E. Are major constituents of basement membranes |
Are major constituents of basement membranes
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133. Which of the following cells produce a specialized form of extracellular matrix?
A. Fibroblast B. Chondroblast C. Mast cell D. Macrophage E. Endothelial cell |
Chondroblast
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134. Which of the following is an example of a proteoglycan?
A. Collagen B. Elastin C. Fibronectin D. Aggrecan E. Hyaluronan |
Aggrecan
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135. Which component of the extracellular matrix provides compressibility?
A. Elastin B. Adhesin C. Hyaluronan D. Collagen E. Integrins |
Hyaluronan
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136. Which of the following is NOT contained in an aggrecan aggregate?
A. Hyaluronan B. Link proteins C. Core protein D. Keratan sulfate E. All of the above would be found |
All of the above would be found
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137. Following digestion of a protein you find many proline, glycine and hydroxylysine molecules, making you believe that this protein was
A. Collagen B. Integrin C. Elastin D. Hyaluronan E. Chondroitin sulfate |
Collagen
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138. You could expect to find prolyl hydroxylase in the
A. Mitochondrial matrix B. Cytosol C. Golgi apparatus D. Cell membrane E. Extracellular fluid |
Golgi apparatus
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139. Elastin
A. Monomers can be linked by desmosine rings B. Contains hydrophobic regions which provide it with elasticity C. Requires the presence of fibrillin for proper integrity D. Degradation can result in emphysema E. All of the above are correct |
All of the above are correct
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140. Which of the following proteins is a dimer important for connecting matrix components?
A. Collagen B. Keratin C. Fibronectin D. Laminin E. Integrin |
Fibronectin
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141. Which of the following would be most effective in dissolving the ground substance?
A. Collagenase B. Hyaluronidase C. Glacial acetic acid D. Trypsin E. Cortisol |
Hyaluronidase
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142. Which of the following is NOT a fibrous protein?
A. Hyaluronan B. Collagen C. Elastin D. Fibronectin E. Laminin |
Hyaluronan
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143. An important function of glycosaminoglycans is to produce
A. Tensile strength in tendons B. Tensile strength in bone C. Elasticity in tendons D. Filtration in the kidney E. Turgor for cushioning in many tissues |
Turgor for cushioning in many tissues
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144. Which of the following would be the best indicator of collagen digestion?
A. Proline B. Glycine C. Hydroxylysine D. Glucuronate E. Iduronate |
Hydroxylysine
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145. Collagen fibrils are formed in
A. Mitochondria B. Rough endoplasmic reticulum C. Golgi apparatus D. Extracellular fluid E. Disease states only |
Extracellular fluid
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146. Which component of the extracellular matrix is associated with formation of the scaffolding used to guide formation of the basal lamina?
A. Keratin B. Fibronectin C. Laminin D. Perlecan E. Integrin |
Laminin
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147. Which component of the extracellular matrix is used to link cells to the matrix, and can also serve as a cell surface receptor?
A. Integrin B. Collagen C. Entactin D. Laminin E. Fibronectin |
Integrin
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148. Which of the following statements concerning collagen is INCORRECT?
A. Collagen has a trihelical structure B. The molecular weight of collagen is above 100,000 C. Hydroxyproline is incorporated into the molecule by tRNA D. Destruction of collagen can be caused by collagenases E. Collagen contains both hydroxyproline and hydroxylysine residues |
Hydroxyproline is incorporated into the molecule by tRNA
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149. Ferrous iron, α-ketoglutarate, molecular oxygen and ascorbate are cofactors for
1. lysyl oxidase 2. procollagen peptidase 3. prolyl hydroxylase 4. galactosyl transferase 5. lysyl hydroxylase A. 1, 3 and 5 B. 1, 2 and 3 C. 1 and 3 only D. 2 and 4 only E. 3 and 5 only |
3 and 5 only
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150. Lysyl oxidase forms intermolecular crosslinks between both collagen and elastin monomers. Which amino acid residues are affected by this enzyme?
A. Hydroxylysine B. Hydroxyallysine C. Hydroxyproline D. Allysine E. Lysinonorleucine |
Hydroxylysine
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151. Cartilage contains
1. Type I collagen 2. Type II collagen 3. Type III collagen 4. Chondroitin sulfate proteoglycan 5. Hyaluronic acid A. 1, 4 and 5 B. 2, 4 and 5 C. 3, 4 and 5 D. 2 and 4 only E. 2 and 5 only |
2 and 4 only
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152. The amino acid composition of collagen (Type I) is characterized by the presence of
1. Cysteine 2. Hydroxyproline and hydroxylysine 3. No sulphur-containing amino acids 4. Glycine as nearly 1/3rd of the total amino acids 5. A high content of aromatic amino acids A. 1, 2 and 4 B. 1, 3 and 5 C. 2 only D. 2, 3 and 4 E. 2 and 4 only |
2 and 4 only
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153. Glycine is found at every third residue in the collagen triple helix. Glycine is important in the structure of collagen because
A. its lack of rotational ability about the α-carbon forces the α-chain into a helical configuration B. its side chain is small and allows the α-chains to fit closely together C. it has many tRNAs and can be made rapidly D. it cannot be hydroxylated E. All of the above |
its side chain is small and allows the α-chains to fit closely together
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154. Elastin is found in
1. Ligaments 2. Cartilage 3. Arteries 4. Tendon 5. Bone A. 1, 2 and 3 B. 2, 4 and 5 C. 1 and 3 only D. 2 and 4 only E. 1 only |
1 and 3 only
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155. Which of the following is NOT a cofactor in the crosslinking reaction of elastin?
A. Copper B. Vitamin B6 C. Molecular oxygen D. Ascorbate E. All of the above are required |
Ascorbate
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156. Elastin provides tissue with
A. Tensile strength B. Multiple binding sites for matrix molecules C. Elasticity D. Sites for water storage E. Binding sites for heme breakdown products |
Elasticity
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157. Fibronectin contains binding domains for all of the following EXCEPT
A. Fibrin B. Collagen C. Heparan sulfate D. Laminin E. Integrin |
Laminin
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158. Cell surface integrin recognizes the following tripeptide sequence on the fibronectin molecule:
A. Arg-Gln-Cys B. Arg-Glu-Ser C. Arg-Gly-Asp D. Arg-Glu-Asp E. Gly-Pro-Hyp |
Arg-Gly-Asp
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159. Laminin consists of how many different polypeptide chains?
A. 1 B. 2 C. 3 D. 4 E. 5 |
3
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160. Laminin, Type IV collagen and heparan sulfate proteoglycan are characteristic of which of the following tissues?
A. Bone B. Cartilage C. Vitreous body D. Glomerular basement membrane E. Epidermis |
Glomerular basement membrane
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161. Integrins contain all of the following domains EXCEPT
A. Matrix binding B. Transmembrane C. Domain of hydrophobic amino acids D. Cytoskeletal attachment E. DNA binding |
DNA binding
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162. Collagen FIBERS are first seen in
A. Rough endoplasmic reticulum B. Smooth endoplasmic reticulum C. Golgi apparatus D. Secretory vesicles E. Osteoid |
Osteoid
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