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 commonly observed?

  Cells lining the small intestine
• Why can't sugars diffuse into the cell from the lumen?

  Higher concentration of sugars inside the cell
• What happens to sugars once they are inside the cell?

  They are transported into the blood
• What role do mitochondria play in active transport?

  They provide energy for active transport
• What ions do root hair cells transport into plants?

  Magnesium ions
• Why do plants need magnesium?

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

  To move ions from soil into the cell
• What happens to ions after they enter root hair cells?

  They are transported to the xylem vessels
• What is the lumen in the context of the small intestine?

  The cavity where food is digested
• What are the key differences between active transport and diffusion?

  • Active transport moves substances against the concentration gradient
  • Diffusion moves substances down the concentration gradient
  • Active transport requires energy from respiration
  • Diffusion does not require energy
• What are examples of active transport in animals and plants?

  • In animals: Absorption of glucose in the small intestine
  • In plants: Uptake of magnesium ions by root hair cells