Osmosis , diffusion , and active transport

    Cards (16)

    • Osmosis is the movement of water particles from an area of high water concentration to an area of low water concentration across a partially permeable membrane
    • A partially permeable membrane has tiny holes in it, allowing small molecules to pass through it, but not karge molecules
      1. Water moves from a high water concentration, outside the cell, to a low water concentration, inside the cell, by osmosis, across a partially permeable membrane, causing the cell to expand
    • 2. Water moves from a high water concentration inside the cell, to a low water concentration outside the cell, by osmosis, across a partially permeable membrane, causing the cell to shrink
    • Diffusion is the net movement of particles from an area of high concentration to an area of low concentration.
    • Diffusion is a passive process, which means it doesn't require energy
    • Diffusion takes place in liquids and gases - because particles move randomly
    • The concentration gradient : the bigger the difference in concentration, the faster the rate of diffusion
    • The surface area to volume ratio : a larger surface area in proportion to the volume will increase rate of diffusion
    • The distance : the shorter the distance, the faster the rate of diffusion
    • The temperature : the higher the temperature, the faster the rate of diffusion
    • Active transport is the movement of particles from a low concentration to a higher concentration
    • Active transport moves UP or against the concentration gradient
    • Active transport requires energy from respiration, in the form of ATP
    • Mineral ions are taken up from the soil by active transport, from a low concentration to a high concentration using energy
    • Carrier proteins in the cell membrane are needed to get molecules e.g. mineral ions into the cells. This process requires energy
    See similar decks