Osmosis and diffusion

Cards (16)

  • 2 components of a cell membrane
    1. Phospholipid
    2. Protein
  • If an animal cell is in a solution that is the same concentration as its cytoplasm, water will move in and out at the same rate
  • If an animal cell is in a solution that is less concentrated than the cell, it will gain water due to osmosis. The cell will enlarge, burst and die
  • If an animal cell is in a solution that is more concentrated than the cell, it will lose water due to osmosis. It will cause the cell to shrivel and die (crenation)
    • Water - solvent
    • Chemical that is dissolved - solute
    • The mixture of these two - solution
  • Osmoregulation
    The active regulation of the osmotic pressure of an organism's body fluids, to maintain the homeostasis of the organism's water content
  • Turgor pressure
    The force of the cell contents against the cell wall in the plant cell
    • If a plant cell is placed in a solution that is highly concentrated, it will lose water
    • The cell membrane shrinks and pulls away from cell wall, leaving a gap between the cell wall and cytoplasm. Process - plasmolysis
  • When the plant loses too much water, it also loses turgor and the plant will wilt
  • Active transport
    The process where chemicals are taken into a cell against the diffusion gradient
  • Active transport is undertaken by proteins in the cell membrane that drag the chemicals into cell
  • Osmosis
    The movement of water from an area of high concentration to an area of lower concentration across a semi-permeable membrane
  • Diffusion
    The movement of molecules from areas of high concentration to areas of lower concentration across a selectively permeable membrane
  • Semi permeable
    Allows some substances to enter and some substances to leave
  • Semi permeable membranes allow some substances through but not others
  • Diffusion is a passive process that does not require any energy