Active transport

• Active Transport

  Absorption of substances against a concentration gradient
• Active Transport in Root Hairs


  1. Root hairs grow into "hairs"

  2. Microscopic hairs cover each branch

  3. Large surface area for absorption

  4. Absorb water and mineral ions

  5. Minerals concentration higher in root hair cells
• Plants need mineral ions for growth
• The concentration of minerals is usually higher in the root hair cells than in the soil around them
• Root hair cells can't use diffusion to take up minerals from the soil
• Active Transport in Plants

  Allows absorption from a dilute solution against a concentration gradient
• Active transport needs energy from respiration to work
• Active Transport in Humans

  Used to take glucose from the gut
• Active Transport in the Gut

  1. Higher concentration of glucose and amino acids in the gut

  2. Diffuse naturally into the blood

  3. Lower concentration of nutrients in the gut

  4. Concentration gradient is the wrong way

  5. Active transport allows nutrients to be taken into the blood
• Active transport allows nutrients to be taken into the blood despite the concentration gradient being the wrong way
• Cells can use diffusion to exchange substances
• Diffusion in Organisms

  • Glucose
  • Amino acids
• A ratio shows how big an area is compared to its volume
• The surface area to volume ratio is important for organisms
• Active transport uses energy
• Text structures and organisation