Active transport

• What is active transport?

  The movement of molecules from a lower concentration to a higher concentration
• Why can't root hair cells use diffusion to take up minerals from the soil?

  The concentration of minerals is usually higher in the root hair cells than the soil around it
• What does active transport need to work?

  Energy from respiration
• When is active transport used in the gut?

  When there is a lower concentration of nutrients in the gut, but a higher concentration of nutrients in the blood