Active transport

• How does active transport differ from diffusion?

  Active transport moves molecules against their concentration gradient, while diffusion moves them down their gradient
• What is diffusion?

  Diffusion is the process by which substances move down their concentration gradient
• Why is diffusion considered a passive process?

  Because it does not require any energy from the cell
• What analogy is used to describe diffusion?

  It is compared to water flowing downhill
• What is active transport compared to in the video?

  It is compared to water moving uphill
• What does active transport require from the cell?

  Energy
• What type of proteins are involved in active transport?

  Special proteins that sit in the membrane
• Where does the energy for active transport come from?

  Cellular respiration in the mitochondria
• What molecule stores energy for the cell?

  ATP
• How is active transport defined?

  As the movement of molecules across a cell membrane from lower to higher concentration requiring energy
• What is an example of active transport in plants?

  • Absorption of water and mineral ions by root hair cells
  • Minerals like magnesium and nitrates are at higher concentration inside the cell
  • Requires energy to move against the concentration gradient
• What adaptations do root hair cells have for their role?

  They have long hair-like protrusions for a large surface area and many mitochondria for energy
• What do root hair cells absorb?

  Water and mineral ions
• Why do root hair cells need to use active transport for mineral ions?

  Because the minerals are at a higher concentration inside the cell than outside in the soil
• What is the role of mitochondria in root hair cells?

  To provide energy for active transport
• What are the key points about root hair cells and active transport?

  • Root hair cells absorb water and minerals
  • They have a large surface area for absorption
  • They contain many mitochondria for energy
  • Active transport is used to move minerals against their concentration gradient