Active Transport

• Osmosis and diffusion are passive processes, this means substances will always move down a concentration gradient.

  Active transport is an active process, this means substances are moved against their concentration, from an area of low concentration to an area of high concentration.
• What is required in order for active transport to take place?

  • Energy is needed for active transport to occur.
• What is the name of the structure which carries molecules across the cell membrane during active transport?

  • A protein carrier which spans the cell membrane.
• Which process released the energy needed for active transport?

  • Respiration releases energy in the form of ATP, this is required for active transport to take place.
• Which organelle is prevalent (more common) in cells that carry out active transport more frequently?

  • Mitochondria is more prevalent in cells where active transport occurs more frequently. Mitochondria is the site of respiration in cells, therefore more energy will be released.
• Root hair cells

  • Plants often live in soil where mineral ions are usually found in dilute solutions, more dilute than the solution within the plants root hair cells. 
  • By using active transport, the plant can still absorb the mineral ions against the concentration gradient.
• Small intestine

  • In humans, an example of active transport is the active absorption of glucose from your gut into your blood. 
  • This is often done against a large concentration gradient. Glucose is needed for respiration so it is important to get as much as possible from the gut.
• State the similarities and differences of diffusion, osmosis, and active transport.