Rate of facilitated diffusion

Cards (9)

  • What does the rate of facilitated diffusion depend on?

    • the concentration gradient
    • the number of channel or carrier proteins
  • Why does the rate of facilitated diffusion depend on the concentration gradient?

    • The higher the concentration gradient, the faster the rate of facilitated diffusion (up to a point)
    • As EQUILIBRIUM is reaches, the rate of FACILITATED DIFFUSION WILL LEVEL OFF
  • Why does the rate of facilitated diffusion depend on the number of channel or carrier proteins?

    Once all the proteins in a membrane are in use, facilitated diffusion cannot happen any faster, even if you increase the conc gradient.
    So the greater the number of channel/carrier proteins in the cell membrane, the faster the rate of diffusion
  • the greater the number of channel/carrier proteins in the cell membrane.......?

    ........ the faster the rate of diffusion!
  • what happens once all the proteins in a membrane are in use?

    facilitated diffusion cannot happen any faster, even if you increase the concentration gradient!
  • What is the effect of having more channel proteins?

    the rate of facilitated diffusion is increased
  • what are Aquaporins?

    special channel proteins that allow the facilitated diffusion of water through cell membranes/
  • give details about Aquaporins?

    • some kidney cells are adapted to have lots of aquaporins
  • what do the aquaporins allow kidney cells to do?

    reabsorb a lot of the water that would otherwise be excreted by the body- about 180 litres need re-absorbing every day