Define the general structure and function of the extracellular matrix. Describe the function and structure of basement membranes. Describe the structures of the components of the extracellular matrix (collagen, fibronectin, laminin, proteoglycans) and differentiate between them. Compare the different mechanisms through which cells adhere to a non cellular surface. Describe the membrane proteins involved in the adhesion of cells to non cellular surfaces. Describe the structures and functions of the different cell junctions. Describe the membrane proteins involved in cell-cell adhesion. Cells are constantly looking around them at their environment and take signals from it. These signals will determine what the cell does. Specialized cell-substratum contact (able to communicate with the basement membrane) Skin is divided into the epidermis and the dermis. All space and any element outside of plasma membrane. Portions of integral membrane proteins and membrane lipids project into the extracellular space.