Cell membrane

• Cell membrane


  a thin double-layered membrane enclosing the cell that controls which substances can move in and out of it
• Fluid mosaic model


  Fluid - refers to the movement of some of the phospholipid and protein molecule within the layers

  Mosaic - made of different components e.g proteins
• selectively permeable


  some substances can pass through while others cannot
• Qualities

  thin - for efficient movement of materials across

  Large surface area - increases the rate of movement of nutrients into wastes

  Flexible - allows unicellular organisms to move
• Roles of the cell membrane

  provide structure

  seperates cytoplasm from the external environment

  Controls the movement of substances that move in and out of the cell