Diffusion

• What is diffusion?

  The movement of particles down a concentration gradient
• In diffusion, do particles move from areas of high concentration to areas of low concentration or vice versa?

  From high concentration to low concentration
• What describes the movement of particles during diffusion before equilibrium is reached?

  Random movement until even distribution
• Even after equilibrium is reached, do particles stop moving entirely?

  No, they continue to move
• What is the net movement of particles like before equilibrium?

  Net movement from high to low concentration
• When does diffusion stop?

  Diffusion doesn't stop, particles are evenly spread
• According to the diagram, where do particles move from initially?

  From high concentration to low concentration
• According to the diagram, what is the end result of diffusion?

  Particles evenly distributed
• Name one factor that increases the rate of diffusion?

  Increasing the temperature
• How does increasing temperature affect diffusion?

  Increases kinetic energy
• What effect does increasing surface area have on diffusion?

  More diffusion across the same time
• How does maintaining a steep concentration gradient affect diffusion?

  Increases the rate of diffusion
• How do cells use diffusion?

  To get particles in and out
• Does diffusion require energy?

  No, it doesn't use energy
• What kind of molecules are suited to diffusing through cell membranes?

  Small molecules
• Name a molecule that enters cells via diffusion.

  Oxygen
• Name a molecule that exits cells via diffusion.

  Carbon dioxide
• According to the last diagram, why will molecules move into the cell?

  Higher concentration outside the cell
• Why is diffusion useful for cells?

  It allows movement of important particles
• Through what kind of membrane do particles pass during diffusion into or out of a cell?

  Selectively permeable membrane