Diffusion

• What is diffusion?

  Movement of particles from high to low concentration
• What happens to gas particles when a barrier is removed?

  They spread out to equalize concentration
• What is a concentration gradient?

  Difference in concentration across a space
• What does 'net movement' mean in diffusion?

  Overall movement of particles in one direction
• What is the definition of equilibrium in diffusion?

  No net movement of particles occurs
• Why is diffusion considered a passive process?

  It does not require metabolic energy
• What does partially permeable mean in relation to cell membranes?

  Some substances can pass through, others cannot
• What factors affect the rate of diffusion?

  • Concentration gradient
  • Size of particles
  • Temperature
  • Surface area of the membrane
  • Distance of diffusion
  • Presence of protein channels
• How does the concentration gradient affect diffusion rate?

  Greater gradient increases the rate of diffusion
• Why can't charged particles diffuse through the cell membrane?

  Due to the hydrophobic core of the membrane
• Can water molecules diffuse through the cell membrane?

  Yes, because they are very small
• How does particle size affect diffusion rate?

  Smaller particles generally diffuse faster
• How does temperature influence diffusion?

  Higher temperature increases kinetic energy and diffusion
• Why do mammals and birds maintain a constant body temperature?

  To ensure consistent diffusion rates
• How does surface area affect the rate of diffusion?

  Larger surface area increases the rate of diffusion
• Why are cell membranes extremely thin?

  To facilitate faster diffusion rates
• What is facilitated diffusion?

  Diffusion through protein channels in the membrane
• What is the relationship between diffusion and concentration gradients?

  • Diffusion occurs from high to low concentration
  • Concentration gradients drive the movement of particles
  • Equilibrium is reached when concentrations equalize
• What are the implications of diffusion being a passive process?

  • No energy expenditure by the cell
  • Allows for efficient transport of substances
  • Relies on natural concentration gradients