CAS BI 108 Lecture Notes - Lecture 11: Extracellular Matrix, Tight Junction, Cell Adhesion
21 Feb 2017
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Document Summary
Cells ( ex in tissue) interact (adhesion) which requires unique cell-cell recognition. Tight junctions- membranes are tightly connected (think of it like stitches and look like quilts: proteins form tight junctions, intercellular space- space between two cells. Desmosomes- loose seals that are like a mesh o space is continuous: protein mesh produce desmosomes, gap junctions- protein tubes (channels) allow substances to travel between cells. Cells can also attach to protein mesh on the outside, called extracellular matrix. Extracellular matrix (protein mesh: collagen bers and proteogylcans) Integrin proteins- (24 types) connect extracellular matrix with the cytoskeleton. Example: imagine a beaker with a drop of red dye after some time, the red dye will spread throughout the solution (diffuses until randomly distributed) Passive transport: simple diffusion, diffusion through channel, and facilitated diffusion o uses a concentration gradient to drive the transport. Active transport: requires energy to go against the concentration gradient.
