BI236 Lecture Notes - Lecture 17: Fibril, Scurvy, Cell Culture
Document Summary
Chapter 17: beyond the cell: cell adhesions, cell junctions and extracellular. Many cells spend all their lives in contact with neighboring cells. The organizaion of cells into issues allows muli-cellular organisms to adopt complex structures and perform complex funcions. We are mulicellular organisms, our cells have learned to sick together; our skin, are epithelial cells stuck together etc. Cells us many mechanisms to sick together, in order for us to exist. Polarized (one side is completely diferent from other side, side= membrane) Epithelium: sheets of cells that are polarized, with discrete funcional domains at opposite ends of the cells. Cells can be atached to each other or to ecm (extracellular matrix) or both. Transmembrane proteins mediate cell-cell adhesion: animal cells use specialized adhesion receptors to atach to one another. Ex. plasmodesmata: many of these are transmembrane proteins; the extracellular domains on neighboring cells interact with each other. The interacion is dynamic; adhesion proteins are coninuously recycled, not stagnant.
