diffusion

• What is the definition of diffusion?

  Diffusion is the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.
• What does the term "net movement" mean in the context of diffusion?

  Net movement refers to the overall movement of particles from one area to another.
• Which three molecules move in and out of cells by diffusion?

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

  Cells need oxygen for respiration, which is carried out by mitochondria.
• How does the concentration of oxygen outside the cell compare to that inside the cell?

  The concentration of oxygen is higher outside the cell than inside the cell.
• What happens to oxygen molecules during diffusion?

  Oxygen molecules move from an area of higher concentration to an area of lower concentration, entering the cell.
• What is produced as a waste gas during respiration?

  Carbon dioxide is produced as a waste gas during respiration.
• How does carbon dioxide move in relation to the concentration gradient?

  Carbon dioxide moves out of the cell by diffusion from an area of higher concentration to an area of lower concentration.
• What is urea and how does it move out of cells?

  Urea is a waste product produced inside cells that diffuses out into the blood plasma.
• What are the three main factors that affect the rate of diffusion?

  The three main factors are the difference in concentrations, temperature, and surface area of the membrane.
• What is the concentration gradient?

  The concentration gradient is the difference in concentration between two areas.
• How does a greater concentration gradient affect the rate of diffusion?

  A greater concentration gradient results in a faster rate of diffusion.
• How does temperature affect the rate of diffusion?

  A higher temperature increases the rate of diffusion because particles have more kinetic energy and move faster.
• How does surface area of the membrane influence diffusion?

  A larger surface area of the membrane increases the rate of diffusion.
• What is the relationship between surface area and diffusion rate in cells?

  • Larger surface area leads to greater diffusion rate.
  • Smaller surface area leads to slower diffusion rate.
• Where can students find questions on diffusion related to this material?

  Students can find questions on diffusion in the vision workbook linked in the video.
• What should students be able to do by the end of the video on diffusion?

  • Describe what is meant by diffusion.
  • Describe the factors that affect the rate of diffusion.