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Concentration Gradients and Diffusion quiz

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  • What is a concentration gradient?
    A concentration gradient is a difference in the concentration of a substance between two areas.
  • When does a concentration gradient exist between two areas?
    A concentration gradient exists when one area has a higher or lower concentration of a substance than another area.
  • What does it mean for a molecule to move down its concentration gradient?
    It means the molecule moves from an area of high concentration to an area of low concentration.
  • Does moving down a concentration gradient require energy?
    No, moving down a concentration gradient does not require energy.
  • What does it mean for a molecule to move up its concentration gradient?
    It means the molecule moves from an area of low concentration to an area of high concentration.
  • Does moving up a concentration gradient require energy?
    Yes, moving up a concentration gradient requires energy.
  • How is the movement of molecules down a concentration gradient similar to a biker going downhill?
    Both require no extra energy; the movement happens naturally.
  • How is the movement of molecules up a concentration gradient similar to a biker going uphill?
    Both require energy to move against the natural direction.
  • What is diffusion?
    Diffusion is the net movement of a substance from an area of high concentration to an area of low concentration.
  • What is the natural tendency of molecules regarding diffusion?
    Molecules naturally tend to move down their concentration gradient from high to low concentration.
  • In the example of dye in water, what happens after the dye is added?
    The dye molecules diffuse from the area of high concentration to areas of low concentration until evenly distributed.
  • What does equilibrium mean in the context of diffusion?
    Equilibrium is when the concentration of the substance is equal throughout the entire area.
  • What are the water and dye molecules represented by in the diffusion example image?
    Water molecules are represented by blue circles, and dye molecules are represented by red circles.
  • Why does diffusion continue until equilibrium is reached?
    Diffusion continues because molecules move from high to low concentration until the concentrations are equal everywhere.
  • Is energy required for diffusion to occur?
    No, diffusion does not require energy because molecules move naturally down their concentration gradient.