Specification: 1.1.2 Cell Membranes

- outline the roles of membranes within cells and at the surface of cells; 
- state that plasma (cell surface) membranes are partially permeable barriers; 
- describe, with the aid of diagrams, the fluid mosaic model of membrane structure  
- describe the roles of the components of the cell membrane;
      - phospholipids
      - cholesterol
      - glycolipids
      - proteins
      - glycoproteins
- outline the effect of changing temperature on membrane structure and permeability; 
- explain the term cell signaling; 
- explain the role of membrane-bound receptors as sites where hormones and drugs can 
   bind; 
- explain what is meant by:
      - passive transport (diffusion and facilitated diffusion including the role of membrane proteins)
      - active transport
      - endocytosis
      - exocytosis;
- explain what is meant by osmosis, in terms of water potential. (No calculations of water potential will be required); 
- recognise and explain the effects that solutions of different water potentials can have upon plant and animal cells