Quiz
Extracellular Matrix
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Questions in this quiz (7)
1 • The ECM is a network of macromolecules that fill the space between cells
• Two main macromolecules make up the ECM
§ Polysaccharide chains of glycosaminoglycans (GAG) that is usually linked to proteins to form proteoglycans.
§ Fibrous proteins of two functional types:
□ a) mainly structural (e.g. [blank_start]collagen[blank_end] and [blank_start]elastin[blank_end])
□ b) mainly [blank_start]adhesive[blank_end] (e.g. [blank_start]fibronectin[blank_end] and [blank_start]laminin[blank_end])- Alaminin
- Bfibronectin
- Celastin
- Dcollagen
- Eadhesive
2 • Physiologic Role of Proteoglycans
○ Sulfated glycoseaminoglycans attached to a large [blank_start]rod[blank_end]-shaped protein in cell membrane
○ Functions as [blank_start]lubricants[blank_end] and structural components in connective tissue - lubrication and fluid balance
○ [blank_start]Supportive[blank_end] element in connective tissues – important components of cartilage (serves as a shock absorber)
○ [blank_start]Mediate[blank_end] the adhesion of cells to the extracellular matrix
○ [blank_start]Bind[blank_end] factors that regulate cell proliferation
○ [blank_start]Antithrombic[blank_end] (dermatan sulfate and heparan sulfate)
[blank_start]Blood[blank_end] lipid clearing- AAntithrombic
- BBind
- CMediate
- DSupportive
- Elubricants
- Frod
- GBlood
3 • Syndecans
○ Syndecans are cell-surface proteoglycans expressed by epithelial and nonepithelial cells that bind to collagens and multi-adhesive matrix proteins such as fibronectin, [blank_start]anchoring[blank_end] cells to the ECM.
○ These are type I integral membrane proteins that consist of [blank_start]transmembrane[blank_end] core proteins with attached heparan sulfate proteoglycans.
○ Exhibits cell type-specific distribution (ex., endothelial cells express syndecan-1, -2, & -4, predominantly targeted to basolateral surfaces).
○ They have homologous transmembrane and cytoplasmic domains that contain four well-conserved tyrosine residues, which might serve important roles for biological function.
○ Syndecan-1 binds [blank_start]chemokines[blank_end] (chemotactic cytokines) and plays a crucial role in inflammation.
Damage to the epithelia release these complexes which then form a chemotactic gradient that attracts [blank_start]neutrophils[blank_end] to the site.- Achemokines
- Bneutrophils
- Ctransmembrane
- Danchoring
4 • Glypicans
○ The glypican family members possess an extracellular region with GAG attachment sites, and a COOH-terminal glycosylphosphatidylinositol ([blank_start]GPI[blank_end]) anchor.
○ Glypican family members are selectively expressed on different cell types with only glypican-1 present on vascular endothelial cells, mainly targeted to apical surfaces.
○ Glypican may play a role in regulating the biological activity of fibroblast growth factors.
• Perlecans
○ The major secreted proteoglycan in [blank_start]basal lamina[blank_end]
○ Consists of a large multi-domain core protein with 3 or 4 [blank_start]specialized[blank_end] GAG chains
Binds to and cross-links many ECM components and cell surface molecules- AGPI
- Bspecialized
- Cbasal lamina
5 • Glypicans
○ The glypican family members possess an extracellular region with GAG attachment sites, and a COOH-terminal glycosylphosphatidylinositol ([blank_start]GPI[blank_end]) anchor.
○ Glypican family members are selectively expressed on different cell types with only glypican-1 present on vascular endothelial cells, mainly targeted to apical surfaces.
○ Glypican may play a role in regulating the biological activity of fibroblast growth factors.
• Perlecans
○ The major [blank_start]secreted[blank_end] proteoglycan in basal lamina
○ Consists of a large multi-domain core protein with 3 or 4 specialized [blank_start]GAG[blank_end] chains
Binds to and cross-links many ECM components and cell surface molecules- AGPI
- BGAG
- Csecreted
6 • Adhesive Glycoproteins
○ These are a group of glycoproteins that link components of the extracellular matrix together and to the cells. These proteins are involved in the following:
§ [blank_start]Wound[blank_end] Healing
§ Cell [blank_start]Attachment[blank_end]
§ Cell [blank_start]Migration[blank_end]
§ Cell [blank_start]Spreading[blank_end]
[blank_start]Chemotaxis[blank_end]- AWound
- BAttachment
- CMigration
- DSpreading
- EChemotaxis
7 • Fibronectin: a large glycoprotein formed by [blank_start]fibroblasts[blank_end] and [blank_start]endothelial[blank_end] cells.
○ It is involved in the attachment and migration of cells (e.g., inflammatory cells) and probably in cellular growth and is present along cell surfaces and basement membranes.
○ Contains:
§ [blank_start]integrin[blank_end]-binding sites
§ binding sites for [blank_start]collagen[blank_end] & [blank_start]glycosaminoglycans[blank_end]
• Laminin
○ The most common [blank_start]adhesive[blank_end] glycoprotein in basement membranes.
○ It binds extracellular matrix components (e.g., collagen) to specific cell surface receptors and assists in [blank_start]capillary[blank_end] tube formation in [blank_start]angiogenesis[blank_end].
• Integrin
○ Integrin connects the extracellular matrix with the [blank_start]actin[blank_end] cytoskeleton inside the cell
○ Major cellular receptors for ECM proteins
Main way that cells both bind to and respond to the ECM- Aintegrin
- Bcollagen
- Cglycosaminoglycans
- Dactin
- Ecapillary
- Fangiogenesis
- Gadhesive
- Hfibroblasts
- Iendothelial
Information
- Description
- Biochemistry Quiz on Extracellular Matrix, created by Fatima G. on 25/08/2019.
- Author
- Fatima G.
- Language
- English
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- 1
- History
- Created on 25 Aug 2019 · updated on 25 Aug 2019
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