Diffusion

• What are the three transport processes that living organisms use for exchange?

  Diffusion, osmosis, and active transport
• What is diffusion?

  Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration.
• How does temperature affect the rate of diffusion?

  Higher temperatures increase the kinetic energy of particles, leading to faster diffusion.
• Why is the cell membrane described as partially permeable?

  Because it allows some substances to pass while blocking others.
• Which substances can diffuse across the cell membrane during gas exchange?

  Oxygen and carbon dioxide
• What happens to carbon dioxide concentration in a photosynthesising leaf cell during the day?

  The concentration is lower inside the cell compared to the environment.
• How does the concentration gradient affect the movement of substances by diffusion?

  The movement is driven by the concentration gradient between the cell and its environment.
• What are the key characteristics of diffusion?

  • Passive process
  • Movement from high to low concentration
  • Driven by kinetic energy of particles
• What is an example of diffusion in everyday life?

  Diffusion of perfume particles through a room
• What must happen for substances to enter or exit a cell?

  They must be able to diffuse through the cell membrane.
• What is the significance of the concentration gradient in diffusion?

  It determines the direction and rate of movement of substances.
• What is the waste product produced by liver cells that must diffuse out?

  Urea
• Why must carbon dioxide diffuse out of cells?

  It is a waste product of aerobic respiration.
• What happens to the diffusion of carbon dioxide at night in a leaf cell?

  The concentration inside the cell is higher than in the environment.
• What are the implications of diffusion for cellular processes?

  • Essential for gas exchange
  • Influences nutrient uptake
  • Affects waste removal