Diffusion

• What is diffusion?

  Net movement of particles from high to low concentration
• How do molecules behave when left alone?

  They move about randomly
• What happens to molecules that are bunched up over time?

  They spread out evenly in space
• What is the definition of net movement in diffusion?

  Movement of all particles considered together
• Can diffusion occur in gases and liquids?

  Yes, it can occur in both
• What is an example of diffusion in gases?

  Perfume spreading in a room
• What is an example of diffusion in liquids?

  Food coloring diffusing in water
• What type of membranes allow diffusion?

  Partially permeable membranes
• What types of molecules can generally diffuse through cell membranes?

  Small molecules like water and glucose
• Why can't larger molecules diffuse through cell membranes?

  They are too big to fit through
• Is diffusion an active or passive process?

  Passive process
• What does it mean that diffusion is a passive process?

  It doesn't require energy from the cell
• What is the first factor that affects the rate of diffusion?

  The concentration gradient
• What is a concentration gradient?

  Difference in concentration between two places
• How does a larger concentration gradient affect diffusion?

  It increases the rate of diffusion
• What is the second factor affecting the rate of diffusion?

  Temperature
• How does temperature affect diffusion?

  Higher temperatures increase particle movement
• What is the last factor that affects the rate of diffusion?

  Surface area
• How does a larger surface area affect diffusion?

  It increases the rate of diffusion
• What are the three factors that affect the rate of diffusion?

  • Concentration gradient
  • Temperature
  • Surface area
• How does diffusion occur across cell membranes?

  • Partially permeable membranes allow diffusion
  • Small molecules can pass through
  • Larger molecules cannot pass through
• What is the overall process of diffusion?

  • Random movement of particles
  • Movement from high to low concentration
  • Results in even distribution over time