Cell Adhesion (HL) (HL IB Biology)

• In order for an organism to be multicellular, its cells need to adhere, or stick, to one another to form tissues
• The plasma membrane is responsible for cell adhesion and this can be permanent or temporary
• Cell adhesion molecules (CAMs) are required to carry out cell adhesion
  • CAMs are a type of cell surface protein
  • They work by binding cells with other cells or with the extracellular matrix
    • The extracellular matrix contains supporting structures, such as collagen proteins, and provides support for the cells
  • Different CAMs are present in different types of cell-cell junction
• Examples of different cell-cell junctions include:
  • Tight junctions
  • Adherens junctions
  • Desmosomes
  • Gap junctions

Cell adhesion diagram

Cell adhesion involves the binding of CAMs to other cells or to the extra-cellular matrix

Different types of cell-cell junction contain different CAMs