Osmosis

Cards (27)

  • Diffusion is the movement of particles down a concentration gradient whereas active transport is against
  • Active transport requires energy from respiration whereas diffusion doesn't
  • Active transport requires a membrane protein to help move molecules whereas diffusion doesn't
  • Lungs
    • Has many folded alveoli which increases its surface area
    • Alveoli are one cell thick so the diffusion distance for oxygen is shorter
    • A good blood supply maintains a high concentration gradient
  • Solute
    Something that can be dissolved
  • Solvent
    The liquid the solute dissolves into
  • Adding salt to vegetables before cooking causes water to leave the cells
  • Osmosis
    The movement of water from an area of higher water concentration to lower water concentration across a partially-permeable membrane
  • Osmosis
    1. Water molecules diffuse from where there is a higher concentration of water to a lower concentration of water
    2. OR
    3. From where there is a lower concentration of solute towards where there is more solute e.g. dissolved salt or sugar
    4. This happens until the concentration is equal on either side of the semi-permeable membrane
  • Osmosis
    • pure water
    • dilute solution
    • concentrated solution
  • Root hair cell vacuoles contain a high concentration of salts and sugars
  • If too much fertilizer is put into the soil in one go, a problem might occur
  • Concentration of sugar solution (M)
    • 0 (distilled water)
    • 0.4
    • 0.8
    • 1.0
  • Results table
    • Initial mass of potato (g)
    • Final mass of potato (g)
    • Change in mass (g)
    • Percentage change in mass (%)
  • Isotonic solution
    Concentration of water inside the cell is the same as the outside
  • Hypertonic solution

    Concentration of water outside the cell is lower than inside
  • Hypotonic solution

    Concentration of water outside the cell is higher than inside
  • Plasmolysed
    Concentrated solution
  • Burst
    Dilute solution
  • Osmosis
    1. The movement of water from an area of high water concentration to an area of low water concentration through a partially-permeable membrane
    2. The solute is too large to pass through the gaps, but water molecules are small enough
    3. Water moves to an area where there is a lower solute concentration
  • Osmosis is the diffusion of water molecules from a dilute solution to a more concentrated solution, across a partially-permeable membrane
  • OSMOSIS IS THE MOVEMENT OF WATER FROM AN AREA OF HIGH WATER CONCENTRATION TO AN AREA OF LOW WATER CONCENTRATION ACROSS A PARTIALLY-PERMEABLE MEMBRANE
  • A partially-permeable membrane has holes in it that permit water molecules through but are too small to allow larger (solute) molecules through
  • People pour salt on slugs to kill them because it causes osmosis, drawing water out of the slug's cells
  • Results table
    • Concentration of sugar solution (M)
    • Initial mass of potato (g)
    • Final mass of potato (g)
    • Change in mass (g)
    • Percentage change in mass (%)
  • Independent variable
    x axis
  • Dependent variable
    y axis