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40 Cards in this Set
- Front
- Back
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Tight junctions
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cell cell
seal cells and create a largely impermeable border prevent diffusion between apical and basallateral domains of cells |
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Adherens junctions
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cell cell
both zonula adherens and desmosomes use cadherins in homotypic binding also use integrins to bind to the extracellular matrix also bind cytoskeleton primarily for strength |
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Channel Forming junctions
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gap junctions
allow movement of small molecules and ions between two cells allows for synchronization in heart and positional information in embryo development |
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anchoring junctions
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hemidesmosomes cell-matrix
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Main components in tight junctions
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claudins also occludins but claudins more characteristic
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desmosomes
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desmogleins and desmocollins in the middle
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zonula adherens
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connects actin bundle
cadherins mediate transmembrane can tighten belt of actin with myosin to pinch off espeically during neural tube development |
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Pemphigus
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skin blistering caused by antibodies towards desmogleins
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composition of gap junction
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connexon pores which are made from 6 connexins
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Regulation of Gap Junction
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pH
Ca Extracellular signals |
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Types of binding in cell adhesion
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1. homo
2. hetero |
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cell cell adhesion
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allows for differentiation in embryo
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cadherins
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regulate calcium dependent cell cell adhesion
E and N cadherin will separate based on type of cadherin cell expresses as well as the level the cell expresses |
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Selectins
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mediate transient cell cell adhesions in the blood stream
binds oligosaccharides necessary for WBC week adhesion and rolling in immune response |
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integrin
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links with ECM
transmenbrane receptors linked to cytoskeleton and binds to RGD domain in ECM proteins binding is not static binds ICAM mediates transient cell cell adhesions in the blood stream binds ICAM necessary for WBC strong adhesion and emigration |
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CAMS
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cell adhesion molecules
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N-cam
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nerve
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ICAM
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immune response
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glycosaminoglycans (GAG)
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help make up the ground substance of the extracellular matrix and resists mechanical force
unbranched polysaccharide with repeating dissacharide 1. an amino sugar that is usually sulfated and 2. uronic acid |
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proteoglycans
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help make up the ground substance of the extracellular matrix and resists mechanical force
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Hyaluronan
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lacks the sulfate so has tons of negative charges
huge molecule synthesized from the basal side of the epithelial sheet creates of cell free space for cell migration allows for nutrient diffusion withstands stress and space fills |
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Heparan sulfate
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tons of negative charge and has sulfate
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Decorin
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the a small core protein of proteoglycans what GAGs attach to only attach one GAG
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Type 1 collagen
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fibril forming
polyproline helix hydroxy proline and lysine present Glycine XY repeat so can fit together |
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lysine aldehydes in collagen 1
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covalent cross linking
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collagen synthesis
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synthesized as a pro alpha fiber in the ER then triple helix formation then packaged into secretory vesicle as procollagen once outside the cell is cleaved to produce tropocollagen adn then they aggregate to form fibrils then fibrils aggregate to form fibers
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Ehlers Danlos
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problem with Type 3 collagen poor secretion and prematrue degredation
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Elastin
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highly crosslinked
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Fibrillin
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a component of microfibrils - essential to the integrity of elastin - gene mutated in Marfan’s syndrome
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Marfan's syndrome
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mutation in the FBN1 gene resulting in mutated fibrillin
disproportionate tall stature mitral valve prolaps aortic dilation and rupture |
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Fibronectin
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binds to the ECM and mitigates cellular migration
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Laminin
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has binding sites which bind it to
basal lamina itself to other parts of the basal lamina |
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Type IV Collagen
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has a polyproline helix but interrupted 26 times so more flexible
prevents from forming fibrils |
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Three ways basal lamina organized
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underlies tissues like epithelia
surrounds like muscle acts as a filter around glomerulus |
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What secretes the extracellular matrix?
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Fibroblasts
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Why do gags give you a lot of water
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because the negative charges on the sugar acids attract sodium which in turn attracts water
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aggrecon
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the long protein part of a poteoglycan many GAGs associated the test tube brush back bone
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What step is Vitamin C needed for in the synthesis of collagen
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It is needed for the functioning of prolohydroxylase and lysohydroxylase
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Prolohydroxylase
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hydroxylation of proline for collagen in pro alpha fibres
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lysohydroxylase
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hydroxylation of lysine for collage in pro alpha fibers
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