Active Transport

• What process allows substances to be absorbed against a concentration gradient?

  Active transport
• How does active transport differ from diffusion?

  Active transport moves substances against the gradient
• What is the energy source for active transport?

  Energy from respiration
• What is a concentration gradient?

  Difference in concentration across a space
• In which part of the human body is active transport used to absorb sugars?

  Small intestine
• Why can't sugars diffuse into the cell from the lumen?

  Higher concentration of sugars inside the cell
• Why do plants need magnesium ions?

  To make chlorophyll in leaves
• How do root hair cells use active transport?

  To move ions from soil into the cell
• How does the concentration of ions in soil compare to that in root hair cells?

  Lower concentration in soil than in cells
• What are the two key differences between active transport and diffusion?

  • Active transport moves substances against the gradient
  • Active transport requires energy from respiration
• What are the examples of active transport in animals and plants?

  • In animals: Absorption of sugars in the small intestine
  • In plants: Transport of magnesium ions in root hair cells
• What role do mitochondria play in cells that perform active transport?

  • Provide energy needed for active transport
  • Enable cells to move substances against concentration gradients