Membranes & transport

  • describe and explain the fluid mosaic model of membrane structure, including an outline of the roles of phospholipids, cholesterol, glycolipids, proteins and glycoproteins
  • outline the roles of cell surface membranes including references to carrier proteins, channel proteins, cell surface receptors and cell surface antigens
  • describe and explain the processes of diffusion, facilitated diffusion, osmosis, active transport, endocytosis and exocytosis
  • describe how to investigate simple diffusion using plant tissue and non-living materials, such as glucose solutions, Visking tubing and agar
  • calculate surface areas and volumes of simple shapes (e.g. cubes) to illustrate the principle that surface area to volume ratios decrease with increasing size
  • describe how to investigate the effect of changing surface area to volume ratio on diffusion using agar blocks of different sizes investigate the effects of immersing plant tissues in solutions of different water potential, using the results to estimate the water potential of the tissues
  • explain the movement of water between cells and solutions with different water potentials and explain the different effects on plant and animal cells