1. CELL-TO-CELL JUNCTIONS Michaela Tiffany

2. SURFACE MARKERS Structure: Variable, integral proteins or glycolipids in plasma membrane Function: Identify the cell Example: MHC complexes, blood groups, antibodies

3. SEPTATE JUNCTIONS/TIGHT JUNCTIONS Structure: Tightly bound, leakproof, fibrous claudin protein seal that surrounds the cell Function: Holds cells together such that materials pass through not between the cells Example: Junctions between epithelial cells in the gut

4. ADHESIVE JUNCTION (DESMOSOME) Structure: Variant cadherins, desmocollins, blind to intermediate filaments of cytoskeleton Function: Creates strong flexible connections between cells Found in vertebrates Example: Epithelium

5. ADHESIVE JUNCTION(ADHERENS JUNCTIONS) Structure: Classical cadherins, bind to microfilaments of cytoskeleton Function: Connects cells together Oldest form of cell junction Found in all multicellular organisms Example: Tissues with high mechanical stress, such as the skin

6. ADHESIVE JUNCTION (HEMIDESMOSOME, FOCAL ADHESION) Structure: Integrin proteins bind cell to extracellular matrix Function: Provide attachment to a substrate Example: Involved in cell movement and important during development

7. COMMUNICATING JUNCTION (GAP JUNCTION) Structure: Six transmembrane connexons/pannexin proteins creating a pore that connects cells Function: Allows passage of small molecules from cell to cell in a tissue Example: Excitable tissue such as heart muscle

8. COMMUNICATING JUNCTION (PLASMODESMATA) Structure: Cytoplasmic connections between gaps in adjoining plant cell walls Function: Communicating junctions between plant cells Example: Plant tissues

9. All information in this power point can be found in Mgraw Hill Biology 10th Edition on pages 82-85