Active transport

• What is the best way to understand active transport?

  Compare it with diffusion.
• What is diffusion?

  • Substances move down their concentration gradient
  • From a region of higher concentration to lower concentration
  • Passive process (requires no energy)
  • Like water flowing downhill
• What is active transport?

  The movement of molecules against their concentration gradient from an area of lower concentration to higher concentration.
• How does active transport differ from diffusion?

  • Active transport moves molecules against their concentration gradient (uphill)
  • Requires energy from the cell (active process)
  • Occurs across a cell membrane
  • Requires special proteins for molecule transfer
• What process provides the energy for active transport in the cell?

  Cellular respiration.
• Where does cellular respiration occur in the cell?

  • Primarily in the mitochondria
  • Breaks down glucose to release energy
• What molecule stores the energy produced by cellular respiration?

  ATP (adenosine triphosphate).
• How does ATP function in the cell?

  • Acts like little batteries
  • Takes energy from mitochondria
  • Transfers energy to different parts of the cell
• Define active transport.

  • Movement of molecules across a cell membrane
  • From a region of lower concentration to higher concentration
  • Requires energy from cellular respiration
• Why do plants need to absorb water and mineral ions?

  • To survive
  • Obtain water for life processes
  • Obtain mineral ions for metabolic functions like chlorophyll and protein production
• What structures in plants facilitate water and mineral ion absorption?

  • Network of roots protruding into the soil
  • Root hair cells on the outside of roots
• What adaptations do root hair cells have for absorption?

  • Long hair-like protrusions into the soil
  • Large surface area for absorption
• What process do root hair cells use to absorb minerals from the soil?

  Active transport.
• Why can't minerals in the soil enter plant cells by diffusion?

  The concentration of minerals inside the cell is higher than outside in the soil.
• What are the key adaptations of root hair cells for mineral absorption?

  • Large surface area
  • Many mitochondria
• What adaptation do root hair cells have to support active transport?

  • Lots and lots of mitochondria to provide ATP energy