Diffusion + surface area : volume (ratio)

• Diffusion

  The movement of molecules from an area of higher concentration to an area of lower concentration
• In diffusion..

  • Particles will move in both directions, but there will be a net movement from higher to lower concentration
  • When fully spread, they will still continue to move
• What is this?

  Diffusion

  
• What is a solute?

  The dissolved substance in a solution
• What is a solvent?

  The liquid in which the solute dissolved to form a solution
• What is a solution?

  Mixture formed by a solute and a solvent
• What is the concentration gradient?

  The difference in concentration of a substance between 2 areas
• The concentration gradient effect:

  The greater the difference in concentration, the quicker the rate of diffusion
• Why does higher temperature make diffusion quicker?

  The particles will have Increased kinetic energy, therefore they will move and mix more quickly
• The greater the surface area…

  The faster the rate of diffusion
• Why will puppies lose body heat quicker than adult dogs?

  Dogs loose heat over their body surface

  Puppies have a much larger surface area to volume ratio
• Large organisms

  • Have a very low surface area to volume ratio..
  • So they have mechanisms to increase surface area proportionally - such as: absorbing areas, adaptions of shape, transport systems (to reduce diffusion)
• Cube diagram

  surface area to volume ratio