Cell transport

    Cards (17)

    • Transport proteins that assist with diffusion create concentration gradients to drive the movement of molecules.
    • Osmosis is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration until equilibrium is reached.
    • What is osmosis?
      Movement of water molecules through a semi permeable membrane
    • Active Transport - requires energy (ATP) to move against its concentration gradient
    • The rate of diffusion depends on temperature, surface area and concentration gradient
    • Diffusion is the net movement of particles from an area of high concentration to an area of low concentration
    • Active processes require energy input
    • Passive Processes do not require energy input
    • Passive Processes do not use ATP or any other form of energy
    • In diffusion, particles move randomly
    • Anaerobic conditions are conditions where there is no oxygen present.
    • The greater the concentration gradient, the faster the rate of diffusion
    • water molecules will move through the membrane in both directions, but the net (overall) movement of water will be from the dilute solution to a concentrated solution.
    • Exchange surfaces are surfaces that are adapted to maximise the efficiency of gas and solute (a substance dissolved in a liquid) exchange across them.
    • Exchange surfaces have a large surface area
    • How does having a large surface area increase the rate of diffusion?
      It allows more of a substance to diffuse at the same time
    • Exchange surfaces tend to have a thin membrane