active transport

• What is active transport in cells?

  Active transport is a process that moves substances in and out of cells against the concentration gradient.
• Why does active transport require energy?

  Active transport requires energy because it moves substances against the concentration gradient.
• What do transport proteins do in active transport?

  Transport proteins use energy to move substances against the concentration gradient.
• How do root hair cells utilize active transport?

  Root hair cells use active transport to uptake water and mineral ions from the soil against the concentration gradient.
• In what situation do humans use active transport in the small intestine?

  Humans use active transport to absorb nutrients like amino acids and glucose when their concentration is higher in intestinal cells than in the small intestine.
• Compare diffusion, osmosis, and active transport in terms of energy requirement and direction of flow.

  • Diffusion:
  • Direction: High to low concentration
  • Energy: No (passive)
  • Osmosis:
  • Direction: High to low concentration (water)
  • Energy: No (passive)
  • Active Transport:
  • Direction: Low to high concentration
  • Energy: Yes (against concentration gradient)
• What is the direction of flow for diffusion?

  Diffusion flows from high concentration to low concentration, down the concentration gradient.
• What is the direction of flow for osmosis?

  Osmosis flows from high concentration to low concentration, down the concentration gradient.
• What are examples of substances that diffuse in and out of cells?

  Examples include carbon dioxide and oxygen exchange in lungs, and food particles like glucose from the small intestine into blood.
• How does active transport differ from diffusion and osmosis?

  Active transport moves substances from low concentration to high concentration, requires energy, and uses carrier proteins, while diffusion and osmosis move substances from high to low concentration and do not require energy.
• What is the main difference between osmosis and diffusion?

  Osmosis specifically describes the movement of water, while diffusion involves the movement of various molecules.
• How would you explain the absorption of food molecules from the small intestine?

  Food molecules move in by diffusion if their concentration is lower in the intestinal wall cells, and by active transport if their concentration is higher in the intestinal wall cells.
• What is the role of carrier proteins in active transport?

  Carrier proteins are required to move substances across the membrane during active transport.
• What is the concentration gradient?

  The concentration gradient is the difference in concentration of a substance between two areas.
• Why is respiration important for active transport?

  Respiration provides the energy required for active transport to occur.