cell biology : active transport

• What process allows substances to be absorbed against a concentration gradient?

  Active transport
• How does active transport differ from diffusion?

  Active transport moves substances against the concentration gradient, while diffusion moves them down the gradient.
• What is the energy source required for active transport?

  Energy from respiration
• In which part of the human body is active transport used to absorb sugars like glucose?

  In the cells lining the small intestine
• Why can't sugars diffuse into the cells lining the small intestine?

  Because the concentration of sugars is higher inside the cell than in the lumen.
• What role do mitochondria play in active transport?

  Mitochondria provide the energy needed for active transport.
• What ions do root hair cells transport into plants using active transport?

  Magnesium ions
• Why do plants need magnesium ions?

  To make chlorophyll in the leaves
• How does the concentration of ions in the soil compare to that inside root hair cells?

  The concentration of ions in the soil is lower than inside the root hair cells.
• What happens to the ions after they are absorbed by root hair cells?

  They are transported to the xylem vessels and moved to the leaves.
• What are the key differences between active transport and diffusion?

  • Active transport moves substances against the concentration gradient.
  • Diffusion moves substances down the concentration gradient.
  • Active transport requires energy from respiration.
  • Diffusion does not require energy.
• What are two examples of active transport in biology?

  1. Absorption of glucose in the small intestine.
  2. Transport of magnesium ions in root hair cells of plants.