diffusion

• Diffusion


  The net movement of particles from an area of higher concentration to an area of lower concentration
• Diffusion


  1. Molecules move about randomly

  2. Molecules spread out over time

  3. Molecules become evenly distributed
• Diffusion can happen in both gases and liquids
• Partially permeable membrane


  Only some molecules can diffuse through, like water, glucose, and amino acids. Larger molecules like proteins and starch cannot fit through.
• Diffusion is a passive process that does not require energy from the cell
• Factors affecting rate of diffusion

  • Concentration gradient
  • Temperature
  • Surface area
• Concentration gradient


  The difference in concentration between two places
• Larger concentration gradient


  Higher rate of diffusion
• Temperature


  Higher temperatures give particles more energy, so they move around faster, resulting in higher rate of diffusion
• Surface area


  Larger surface area allows more particles to diffuse in and out at once, resulting in higher rate of diffusion