diffusion and active transport

• What are the two ways substances can move in and out of cells mentioned in the text?

  Diffusion and active transport
• What is diffusion?

  Diffusion is the net overall movement of particles from an area of higher concentration to an area of lower concentration.
• In which states of matter does diffusion occur?

  Diffusion occurs in both liquids and gases.
• What is the role of cell membranes in relation to substances?

  Cell membranes hold the cell together and allow substances to move in and out.
• What types of molecules can diffuse through cell membranes?

  Very small molecules like glucose, amino acids, water, and oxygen can diffuse through cell membranes.
• What is the net movement of particles during diffusion?

  Particles move from an area of higher concentration to an area of lower concentration.
• What is active transport?

  Active transport is the movement of particles across a membrane against a concentration gradient using ATP.
• How does active transport differ from diffusion?

  Active transport moves particles from lower to higher concentration, while diffusion moves them from higher to lower concentration.
• Why is active transport essential in the digestive system?

  Active transport allows nutrients to be taken into the blood even when their concentration is lower in the gut.
• What does active transport require to function?

  Active transport requires ATP from respiration.
• How do plants use active transport?

  Plants use active transport to obtain minerals they need from the soil.
• What is the definition of osmosis?

  • Osmosis is the movement of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
• What is the role of ATP in active transport?

  ATP provides the energy needed to move particles against a concentration gradient.
• What is a concentration gradient?

  A concentration gradient is the difference in concentration of a substance between two areas.