Diffusion, active transport and osmosis

• What is diffusion?

  The net movement of particles from an area of higher concentration to an area of lower concentration
• What types of substances does diffusion take place?

  In liquids and gases because their particles are free to move
• What processes allow substances to move in and out?

  Diffusion, active transport and osmosis
• What are the role of cell membranes?

  holds the cell in place while controlling what goes in and out of it
• What can enter cell membranes?


  Small things such as glucose, amino acids, water and oxygen
• What cant enter cell membranes?

  larger molecules such as starches and proteins
• what is active transport?

  The net movement of particles from an area of low concentration to an area of high concentration across a membrane against a concentration gradient using ATP
• What is an example of active transport in animals?

  Digestion- your small intestine carbohydrates break down into glucose which gets transported into the bloodstream
• What is required for active transport?

  A concentration gradient, a cell membrane and ATP
• What are carrier proteins?

  Special proteins that stretch across the width of a cell membrane
• What is an example of active transport in plants?

  Plants absorbing nitrate ions from soil water into the roots to make proteins for growth
• What does atp stand for?

  Adenine triphosphate
• What type of process is active transport?

  active because it moves particles against the concentration gradient using energy from atp
• How does active transport get energy?

  ATP
• How can active transport help the body?

  It helps a lower concentration of nutrients move into the blood
• What is osmosis?

  The net movement of water molecules across a partially permeable membrane from an area of high water potential to low water potential
• What does osmosis move along?


  A partially permeable membrane
• What is a partially permeable membrane?

  A membrane that only allows small molecules through
• What type of process is osmosis?

  Passive, it does not require any energy
• Where does osmosis go past?


  Down the concentration gradient
• What is water potential?

  the potential of water molecules diffusing in or out of a solution
• What happens to water potential as concentration increases?

  Water potential decreases as theres less water molecules
• why does osmosis happen in plants ?

  The high water potential in soil from watering plants
• What happens if theres no water in the soil?

  The plant wilts (droops) because it becomes flaccid (lacks turgidity)
• What happens when water moves into a plant cell?

  the plant cell absorb water by osmosis.The vacuole grows and pushes the cell membrane against the cell wall. this is called turgor pressure and makes the cell firm or turgid
• What does flaccid mean?

  the cell lacks turgidity
• What does wilt mean?

  Droop
• What does tugor pressure do for the cell?

  It supports the cell
• What is a hypotonic solution?

  A solution that has a lower concentration of solute than water
• What is a hypertonic solution?

  a solution that has has a higher concentration of solute than water
• What is a isotonic solution?

  A solution that has the same concentration of solute as water