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20 Cards in this Set
- Front
- Back
3 types of Junctions between cells
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1Tight occluding juncitons
2 Anchoring Juntions- IF and actin 3 Communicating - gap junctions |
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Characteristics of Tight Juntions
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Made of protein, anchored by actin
Restrict movement of solutes Restrict mobility of membrane proteins Prevent budding |
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Adherens Junctions
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Use the protein Cadherin, use actin filaments, make an adhesion belt
Crucial for embryology |
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IF attachments in cell
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desmosomes cell-cell
hemi-desmosomes cell-ECM Mechanical strength Cadherin family protein binds in between plaques of anchor proteins Held together with Keratin |
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Gap junctions
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For communication, allow particles in between
1000 daltons is the max size for passage Twist shut with high Ca2+ or low ph Snap open with law Ca2+ or high ph Channels are formed by 2 connexon, connexons are made of 6 connexins small, water-soluble ions and molecules |
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3 components of adhesionns
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cytoskeletal filament
cytoskeletal accessory proteins transmembrane proteins |
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Anchoring Links in tight junctions
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occludins, ZO-1
actin |
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Anchoring links in adherens
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E-Cadherin/ catenin
actin |
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anchoring lunks in desmosome
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desmoglein, desmocollin (a cadherin)
plakoglobin intermediate filaments (keratin) |
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Anchoring links in focal adhesions
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integrin
actin |
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anchoring links in hemidesmosomes
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integrins
intermediate filaments (keratins) |
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Characteristics of Cadherins
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Used in tissue differentiation and structure
all transmembrane glycoproteins Three types |
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Characteristics of E-Cadherins
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key adhesion molecule for epithelial cells
required for all cell junctions between adjacent cells ECD intereacts homotypically cytoplasmic domain acts laterally w/ actin filaments in adhesion belt The more E-Cadherin, the less mobility |
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Characteristics of P, N cadherins
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placental and neural cadherins
used those places, lungs, and heart both form homotypic interactions |
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Characteristics of ECM between tissues
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in epithelial tissue it is the basal lamina
Loose connective tissue- less dence, more dispersion of fibroblasts Dense connective tissue- large matrix, dense, few fibros dispersed Strengthened by fibrous proteins and glycosylated proteins |
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Fibroblasts
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create and synthesize the ECM
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Fibrous proteins
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Collagen
- IV types, IV only in basal lamina - Basic unit is triple helix, w/ Gly, Pro, Lys and Gly every 3, packs tight -Elastin: good recoil, spring, - like in diaphragm, lungs, heart, arteries |
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Proteoglycans
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Found in ECM
1 core protein w/serine piece then xylose, galactose, galactose, glucaronic acid then GAG disaccharide or more |
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Types of GAG
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chondroitin- in cartalage and everywhere
keratan- in cartilage herparan- in basal lamina |
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Multiadhesive Matrix Proteins
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Link cells to different matrix components, ECM to ECM too
Funtion: -organize matrix, regulate attachment, regulate cell migration and shape Types - fibronectin, laminin, thrombospondin, vitronectin, entactin, chondronectin |