Active Transport

• when a cell needs to bring in a molecule that it already has a high concentration of inside, active transport takes place
• active transport is the movement of molecules from a more dilute solution to a more concentrated solution across a cell membrane against a concentration gradient
• active transport requires energy from respiration
• active transport and diffusion differences

  active transport moves against while diffusion moves down the concentration gradient

  diffusion doesnt require energy
• examples of active transportin humans

  cells in the human small intestine take in sugars like glucose from the lumen through active transport to transport it into the bloodstream and then the body

  • those cells have lots of mitochondria to provide energy through respiration for active transport
• the lumen is the cavity where food is digested in the small intestine
• in the lumen we find molecules produced from when food was digested such as sugars like glucose
• examples of active transportin plants


  root hair cells transport ions like magnesium from the soil into the plant to make chlorophyll in the leaves. The conc. of magnesium in the soil is lower than the conc. of Mg in the root hair cell so active transport takes place

  the ions are then transported to the xylem vessels and moved to the leaves

  root hair cells have lots of mitochondria providing energy for active transport to happen.