cell transport

• what is diffusion?


  The movement of particles from an area of high concentration to an area of low concentration
• name three factors that affect the rate of diffusion

  1. concentration gradient
  2. temperature
  3. surface area of membrane
• name two ways on how villi are adapted for exchanging substances?

  1. long and thin- increased surface area
  2. one cell thick membrane
• name two ways how lungs are adapted for efficient gas exchange?

  1. large surface area
  2. one cell thick membrane
• name two ways fish gills are adapted for efficient gas exchange?

  1. large surface area
  2. thin layer of cells
• what is osmosis?


  The movement of water molecules from an area of high concentration to an area of low concentration across a semi-permeable membrane.
• what is active transport?

  Movement of molecules across a cell membrane that requires energy. From a low concentration to a high concentration