diffusion

• What is diffusion?

  The spreading out of particles
• What does the term "net movement" mean in diffusion?

  Overall movement from high to low concentration
• What are three molecules that move in and out of cells by diffusion?

  • Oxygen
  • Carbon dioxide
  • Urea
• Why do cells need oxygen?

  For respiration to generate energy
• How does oxygen concentration affect its movement into cells?

  Higher concentration outside leads to diffusion into cells
• What happens to carbon dioxide during diffusion in cells?

  It moves out of the cell due to higher internal concentration
• What is urea and how does it move out of cells?

  Urea is a waste product that diffuses into blood plasma
• What are the three main factors affecting the rate of diffusion?

  1. Concentration gradient
  2. Temperature
  3. Surface area of the membrane
• What is the concentration gradient?

  The difference in concentration between two areas
• How does a greater concentration gradient affect diffusion?

  It increases the rate of diffusion
• How does temperature affect the rate of diffusion?

  Higher temperature increases the rate of diffusion
• Why does higher temperature increase diffusion rate?

  Particles have more kinetic energy and move faster
• How does surface area affect the rate of diffusion?

  Larger surface area increases the rate of diffusion
• Which cell has a greater rate of diffusion: one with a large or small surface area?

  The cell with a larger surface area
• Where can you find questions on diffusion related to this material?

  In the vision workbook linked in the video
• What should you be able to describe by the end of the video?

  The meaning of diffusion and its affecting factors