diffusion

• What is the process called when molecules move randomly in a liquid or gas?

  Diffusion
• What happens to molecules during diffusion?

  They move from high to low concentration
• What is required for diffusion to occur?

  No ATP is needed for diffusion
• What does a concentration gradient represent?

  The difference in concentration between two areas
• How can cells maintain a concentration gradient?

  By using or transporting substances elsewhere
• What does a triangle represent in a concentration gradient?

  • The difference in concentration
  • The direction of net movement
• What occurs at equilibrium in diffusion?

  Molecules continue to move with no net movement
• What factors affect the rate of diffusion?

  1. Concentration gradient
  2. Distance of travel
  3. Surface area of the membrane
  4. Thickness of the membrane
  5. Temperature
  6. Particle size
• How does a greater concentration gradient affect diffusion?

  It increases the rate of diffusion
• How does the distance of travel affect diffusion?


  Shorter distance increases the rate of diffusion
• What effect does a larger surface area have on diffusion?


  It increases the rate of diffusion
• How does membrane thickness affect diffusion?


  Thinner membranes increase the rate of diffusion
• What happens to molecular kinetic energy when temperature increases?


  Kinetic energy increases, boosting diffusion rate
• How does particle size affect diffusion rates?


  Smaller particles diffuse faster than larger ones
• What type of molecules undergo simple diffusion?

  Non-polar molecules like oxygen and carbon dioxide
• What is the characteristic of the graph representing simple diffusion?

  It is a linear (straight line) graph
• How does the rate of diffusion relate to concentration gradient?

  Rate of diffusion is directly proportional to gradient
• What happens to diffusion if respiration is stopped?

  Diffusion continues without ATP
• What is a respiratory inhibitor?

  A substance that stops ATP production
• What is an example of a respiratory inhibitor?

  Cyanide