osmosis

• osmosis definition

  osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to low water concentration
• A selectively permeable membrane


  A membrane that allows certain substances to pass through while preventing others from passing through
• What is osmosis?

  The movement of water across a semipermeable membrane
• What can you observe about osmosis using sugar solutions?

  You can observe the effect of sugar solutions on plant tissue
• What happens when you cut a potato with a dull knife?

  You can see an interesting picture of cell structure as the cells separate
• What are the cell walls of onion cells made up of?

  Cellulose
• How can you observe the walls of onion cells?

  By cutting an onion with a dull knife
• What is the significance of cellulose in plant cells?

  • Provides structural support
  • Forms the cell wall
  • Helps maintain cell shape
• Why is it important to note the repetition of the statement about cellulose in the study material?

  It emphasizes the importance of cellulose in plant cell structure
• What is osmosis?

  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• How does osmosis differ from diffusion?

  Osmosis specifically refers to the movement of water, while diffusion refers to the movement of particles
• What happens to an animal cell placed in pure water?

  Water moves into the cell, causing it to expand and possibly burst
• Why does an animal cell burst when placed in pure water?

  Because the cytoplasm has a relatively low concentration of water compared to the outside
• What occurs when an animal cell is placed in a concentrated solution?

  Water moves out of the cell, causing it to shrink
• What is the effect of osmosis on a plant cell placed in pure water?

  Water moves into the cell, causing it to expand and become turgid
• What prevents a plant cell from bursting when it becomes turgid?

  The cell wall
• What happens to a plant cell when placed in a concentrated solution?

  Water moves out of the cell, causing it to shrink and become flaccid
• What is a partially permeable membrane?

  A membrane that allows some molecules to pass through but not all
• What do scientists mean by a 'dilute solution'?

  A solution that contains a high concentration of water
• What do scientists mean by a 'concentrated solution'?

  A solution that contains a low concentration of water
• How does the concentration of water differ between dilute and concentrated solutions?

  Dilute solutions have a high concentration of water, while concentrated solutions have a low concentration of water
• Osmosis in Plant Cells

  Water entering: turgidity; water leaving: flaccidity
• Osmosis in Animal Cells

  Water entering: expansion, potential bursting; water leaving: shrinkage
• What is osmosis?

  Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• What happens to a plant cell when it is placed in water?

  Water moves into the cell by osmosis, causing the cell to expand
• What occurs when a plant cell is placed in a concentrated solution?

  Water moves out of the plant cell by osmosis, causing the cell to shrink
• What is the typical plant tissue used to investigate osmosis?

  • Potato
  • Other vegetables like beetroot or parsnip can also be used
• Why do we peel the potato before the experiment?

  To prevent the potato skin from affecting osmosis
• What tool is used to produce uniform cylinders of potato?

  A cork borer
• What is the recommended length for the potato cylinders?

  Approximately three centimeters