movement of substances in and out of cells

• diffusion definition

  the net movement of particles from an area of high concentration to an area of low concentration by moving randomly
• osmosis definition

  the movement of water molecules from a region of higher concentration of water molecules (more dilute solution) to a region with a lower concentration of water molecules through a partially permeable membrane
• hypertonic solution


  concentrated
• hypotonic solution


  dilute
• isotonic solution


  equal water and solute concentration
• when an animal cell is placed in a hypertonic solution

  water will leave the cell

  cell will shrink and shrivel

  called crenation
• when an animal cell is placed in an isotonic solution

  water enters and leaves the cell at an equal rate

  shows no change

  cell is in equilibrium with the solution
• when an animal cell is placed in a hypotonic solution

  water will enter the cell

  the cell swells and bursts

  called lysis
• osmosis is basically

  the cell wanting everything to be diluted
• when a plant cell is placed in a hypotonic solution,

  water enters the cell

  fills vacuole

  vacuole swells and presses against cell wall

  called turgor pressure

  cell wall doesn't stretch much

  cell becomes turgid
• when a plant cell is placed in a hypertonic solution

  water exits the vacuole

  vacuole shrinks and pulls cytoplasm away from the cell wall

  cell collapses

  called plasmolysis, causes plants to wilt
• how does concentration gradient affect rate of diffusion

  the greater the concentration gradient (the bigger difference in concentrations), the quicker diffusion will happen
• how does the temperature affect rate of diffusion

  the higher the temperature, the more kinetic energy the particles will have and can therefore move faster so diffusion will happen quicker
• how does distance of travel affect rate of diffusion

  if the particles don't need to move as far, diffusion will happen quicker
• how does surface area to volume ratio affect rate of diffusion

  the bigger the surface area to volume ratio, the faster the rate of diffusion