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
• What happens when a cell needs to bring in a molecule at high concentration inside?

  It uses active transport to absorb it
• Why can't sugars diffuse into the cell from the lumen?

  Because their concentration is lower in the lumen
• What do mitochondria provide for active transport?

  Energy needed for the process
• How do root hair cells in plants utilize active transport?

  To transport ions like magnesium from soil
• Why do plants need magnesium ions?

  To make chlorophyll in the leaves
• What do root hair cells transport into the plant?

  Ions such as magnesium
• How are ions transported after entering root hair cells?

  They are moved 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 gradient
  • Diffusion moves substances down the gradient
  • Active transport requires energy from respiration
  • Diffusion does not require energy
• What role do mitochondria play in cells that perform active transport?

  • Provide energy for active transport
  • Enable cells to absorb necessary substances