Transportation of Particles

• Diffusion is the net movement of particles from a High concentration to a low concentration.
• Osmosis is the movement of water molecules from a high water concentration to a low water concentration through a partially permeable membrane.
• Active Transport is the movement of particles from a low concentration to a high concentration across the concentration gradient. Which uses energy.
• When water moves into a cell, it expands.
• OSMOSIS POTATO PRACTICAL

  
  

  1. Peel Potato
  2. Use Cork Borer to create cylinders
  3. Trim cylinder to same length - 3cm
  4. Measure length - Ruler and Mass - balance
  5. Place cylinders in test tubes
  6. Add Sugar solution 2 two tubes and distilled water to 1.
  7. Wait Overnight for osmosis
  8. Place Potatoes them on tissue to remove any moisture
  9. Record Mass and Length again.

  
• Distilled Water does not contain any dissolved substances.
• Things affecting rate of diffusion

  • Temperature
  • Surface Area
  • Concentration gradient
• If red blood cells were placed in pure water, they would gain water and swell.
• Active Processes require energy. Passives dont.
• Plants absorb mineral ions from the soil.
• small objects have a larger surface area to volume ratio
• Alveoli allow oxygen and carbon dioxide to diffuse in and out of the body/bloodstream
• Villi allow nutrients such as glucose, amino acids, mineral ions etc to be absorbed from the small intestines into the bloodstream
• A good blood supply maintains a strong concentration gradient as blood is constantly replaced
• Why do plants use Active transport instead of diffusion?

  Because the concentration of minerals is higher in the root cell than the soil and the particles move from the soil to the plant (low conc to high conc)