Diffusion

• Osmosis is the diffusion of water across a partially permeable membrane, from an area of low solute to an area of higher levels of solutes.
• Diffusion is the net movement of particles from an area of high concentration to low concentration until equilibrium is reached.
• Osmosis potato practical:

  1. Weigh the potato slices before submerging in solution
  2. Set up 6 test tubes, all with different concentrations of sucrose solution except for one with distilled water
  3. Leave the potato cylinders in the test tubes for 40 minutes
  4. Remove each cylinder from the test tube and use a paper towel to remove excess solution
  5. Weigh the potatoes
• What does the osmosis potato practical investigate?

  The effect of osmosis on plant tissue. The potatoes will decrease or increase in mass if they lose or gain water by osmosis.
• Active transport is the movement of molecules from an area of low concentration to an area of high concentration against a concentration gradient. It uses energy.
• What is an isotonic solution?

  A solution with the same concentration of solutes as the cell.
• What is a hypertonic solution?

  A solution with a higher concentration of solutes than of the concentration of solutes inside of the cell (the cell shrinks)
• What is a hypotonic solution?

  A solution with a lower concentration of solutes than of the concentration of solutes inside of the cell (cell swells)
• What is an example of diffusion?

  Oxygen diffusing from the alveoli to the blood
• What is an example of osmosis?

  Drawing water from plant roots
• What is an example of active transport?

  Glucose in the small intestine