Osmosis and Diffusion

• Homeostasis


  The ability to maintain a stable internal environment despite changes in the external environment
• Passive transport


  Does NOT require energy/ATP
• Active transport


  DOES require energy/ATP
• Passive transport


  • Molecules pass directly through membrane
  • Molecules generally small with little or no electrical charge (O2, CO2, H2O, etc.)
  • Uses channel proteins
• Active transport


  • Movement of larger compounds (i.e. sugar) or those that are ionically charged (i.e. salt)
  • Involves the use of energy (ATP)
  • Uses carrier proteins
• Passive transport


  • Diffusion
  • Osmosis
• Oxygen and water are essential to ALL living organisms
• CO2 is essential to plants and all other photosynthesizers like algae and certain bacteria
• Molecules move randomly from areas of high concentration to areas of low concentration until a balance (equilibrium) is achieved
• • Molecules move randomly from areas of high concentration to areas of low concentration until a balance (equilibrium) is achieved.
• Diffusion:

  • Molecules move randomly from areas of high concentration to areas of low concentration until a balance (equilibrium) is achieved.
• Active Transport movement of larger compounds (i.e. sugar) or those that are ionically charged (i.e. salt)Involves the use of energy (ATP)

  • carrier proteins
• Passive Transport/Diffusion

  • Diffusion and osmosis are examples of passive transport.
  • Oxygen and water are essential to ALL living organisms!  
  • CO2 is essential to plants and all other photosynthesizers like algae and certain bacteria!
• Osmosis:

  • Special type of diffusion where water moves across a selectively permeable membrane until a balance is achieved.
• What happens during Osmosis:

  • During osmosis, water moves from high concentration to low concentration
• Water is called a solvent, molecules dissolved in water are called solutes
• • Three terms to describe the direction in which water molecules will move during osmosis:
  • Hypotonic
  • Isotonic
  • Hypertonic
• • Hypo = less solute  (so, more solvent)
  • Hyper = more solute (so, less solvent)

  Iso = same as (so, equal parts solute and solvent)
• What is diffusion?


  It is when particles diffuse or spread out from eachother. From an area of high concentration to low concentration.
• Diffusion can occur through any kind of membrane that has pores large enough for the particle to pass through.