diffusion

Cards (7)

  • diffusion:
    the net movement of particles from an area with a high concentration to an area with a lower concentration
  • in diffusion particles move down the concentration gradient (from high to low concentration)
  • diffusion is a passive process meaning no energy is required
  • diffusion in humans:
    • nutrients in small intestine diffuse in the capillaries through the villi
    • oxygeon diffuses from the air into alveoli into the capiliary blood
    • carbon dioxide diffuses from the blood in the capillaries into the air into in the alveoli
    • urea diffuses from cells into the blood for excretion in the kidney
  • diffusion in plants:
    • carbon dioxide used for photosynthesis diffuses into the leaves through the stomata
    • oxygen produced during photosynthesis diffuses out of the leaves through the stomata
  • diffusion in fish:
    • oxygen from water passing over the gills diffuses into the blood in the gill filaments
    • carbon dioxide diffuses from the blood in the gill filaments into the water
  • factors that affect the rate of diffusion:
    • difference in concentration - the steeper the concentration the faster the rate of diffusion
    • temperature - the higher the temperature the faster the rate of diffusion
    • surface area of the membrane - the larger the membrane the faster the rate of diffusion