Active Transport/Diffusion

• What are the two main processes by which dissolved substances move into and out of cells?

  Diffusion and active transport
• How does water move into and out of cells?

  By osmosis
• Why is diffusion important in the body?

  It moves oxygen into cells and removes carbon dioxide
• What is the role of active transport in cells?

  It allows cells to absorb minerals from dilute solutions against the concentration gradient
• How do gut cells utilize active transport?

  They absorb glucose from digested food in the gut
• What is the process called that caused the change in the experiment with the tube and beaker?

  Osmosis
• What happens to the water level in the tube during osmosis?

  The water level in the tube increases
• What is osmosis defined as?

  The net movement of water molecules across a partially permeable membrane
• What is one similarity between diffusion and osmosis?

  Both involve the movement of substances across a membrane
• What is one difference between diffusion and active transport?

  Diffusion does not require energy, while active transport does
• If a plant is treated with a poison that prevents respiration, will the root still be able to absorb water and mineral ions from a dilute solution?

  No, because respiration provides the energy for active transport
• What are the methods of substance movement into and out of cells?

  • Diffusion: Movement of solutes from high to low concentration
  • Active Transport: Movement of substances against the concentration gradient using energy
  • Osmosis: Movement of water across a partially permeable membrane
• What is the significance of respiration in active transport?

  • Provides energy for active transport
  • Essential for the absorption of minerals and ions
  • Without respiration, active transport cannot occur
• What are the key components of the experiment involving osmosis?

  • Initial equal levels of solution and water
  • Osmosis causes water to enter the tube
  • The membrane prevents solution from entering the tube
• What are the definitions of diffusion, osmosis, and active transport?

  • Diffusion: Movement of particles from high to low concentration
  • Osmosis: Net movement of water across a semi-permeable membrane
  • Active Transport: Movement of substances against the concentration gradient using energy