biological membranes

• Explain the role of the cell membrane at the surface of the cell


  • contains receptors, so is a site for cell signalling
  • site of chemical reactions
  • regulates transport of materials into and out of the cell (partially permeable)
• Explain the role of the cell membrane within the cell



  • mitochondria have folded inner membranes, called cristae. These give a large surface area for aerobic respiration
  • The inner membranes of chloroplasts, called thylakoids membranes, house chlorophyll. On these membranes some reactions of photosynthesis occurs