osmosis, active transport and diffusion

• Diffusion


  The net movement of particles from an area of higher concentration to an area of lower concentration
• Diffusion


  1. Molecules move about randomly

  2. Molecules spread out over time

  3. Molecules become evenly distributed
• Diffusion can happen in both gases and liquids
• Cell membranes


  • Partially permeable
  • Only small molecules can diffuse through
  • Larger molecules cannot fit through
• Diffusion is a passive process that does not require energy from the cell
• Factors affecting rate of diffusion

  • Concentration gradient
  • Temperature
  • Surface area
• Concentration gradient


  Difference in concentration between two places
• Larger concentration gradient


  Higher rate of diffusion
• Higher temperature


  Higher rate of diffusion
• Larger surface area


  Higher rate of diffusion
• Diffusion


  Net movement of particles from an area of high concentration to an area of low concentration, down a concentration gradient
• Active transport


  Movement of particles from an area of low concentration to an area of high concentration against a concentration gradient, using up energy (ATP), requiring a carrier protein to be present in the membrane
• Processes

  • Diffusion
  • Osmosis
  • Active Transport
• Which of the processes require energy?


  Active Transport
• Which of the processes involves water only?


  Osmosis
• Which of the processes involves movement of particles?

  Diffusion, Active Transport
• Which of the processes must involve a membrane?

  Osmosis, Active Transport
• Which of the processes involves movement from a high to low concentration/water potential?

  Diffusion, Osmosis
• Which of the processes is involved in oxygen moving from the alveoli into the blood?

  Diffusion
• Which of the processes is involved in mineral ions moving from the soil into root hair cells?

  Active Transport
• Which of the processes involves movement from a low to high concentration?

  Active Transport
• Which of the processes doesn't require energy?

  Diffusion, Osmosis
• Which of the processes is involved in water moving from the soil into root hair cells?

  Osmosis
• Which of the processes involves movement down a gradient?

  Diffusion, Osmosis
• Which of the processes is involved in digested food molecules moving from the small intestine into the blood?

  Diffusion
• Which of the processes is involved in moving oxygen, food etc. from the mother's blood to the fetus' blood within the placenta?

  Diffusion, Osmosis
• Which of the processes involves movement against a gradient?


  Active Transport
• osmosis

  net movement of water from an area of high water potential to an area of low water potential across a partially permeable membrane