active transport

• Active transport:

  • Movement from dilute to concentrated solution.
  • Movement of molecules against their concentration gradient, using energy from respiration
• Root hair cells

  • Specialised cells that create an exchange surface with the soil
  • mineral ions needed for plant growth
  • Use energy from respiration to actively transport ions against the concentration gradient and into the cell
• Humans

  • Use active transport to absorb nutrients (such as amino acids and glucose) from the small intestine
  • If the concentration of nutrients in the intestinal cells is higher than the concentration of nutrients in the small intestine, they can't diffuse across passively
  • Active transport allows nutrients to be absorbed into the walls of the intestine against the concentration gradient so they can enter the blood and can be transported around the body to be used for respiration