[M1.3] READ - Movement In & Out of Cells (PowerPoint) v1a.ppt
- 1. IGCSE 2023-25 Biology Resource Topic: 1.3 Movement In and Out of Cells © 2021, Wolsey Hall Oxford. All rights reserved.
- 2. Movement In and Out of Cells
- 3. 15/12/24 3 Movement in Movement in and out of and out of cells cells
- 4. 15/12/24 4 Plant cells vs. Animal cells Plant cells vs. Animal cells Both types of cell have these: Only plant cells have these: Nucleus Cytoplasm Cell wall Permanent vacuole 1) 2) 3) 7) 6) 8) Ribosomes Chloroplasts 5) Mitochondria 4) Cell membrane
- 5. 15/12/24 5 How do substances enter How do substances enter and leave cells and leave cells? ? (transport across boundaries) (transport across boundaries) • There are 3 processes: Diffusion Osmosis Active transport
- 6. 15/12/24 6 Diffusion Diffusion • Diffusion is the movement of all particles from a region of HIGH concentration TO a region of LOW concentration… …until the concentrations are equal – this is called equilibrium
- 7. 15/12/24 7 Examples of Diffusion in Examples of Diffusion in Biology Biology • Oxygen diffuses from the lungs into the blood. •Oxygen diffuses out of the blood into the cells for respiration. •Carbon dioxide diffuses out of blood capillaries into the lungs. •Carbon dioxide diffuses into leaves for photosynthesis.
- 8. 15/12/24 8 Question on diffusion. Question on diffusion. • The drawing below shows four ways in which particles may move in and out of an animal cell. The dots show the concentration of particles (molecules)
- 9. 15/12/24 9 1. The cell is carrying out aerobic respiration (it needs oxygen). Which arrow, A, B, C or D represents: • A) the movement of oxygen particles? • B) the movement of carbon dioxide particles? 2. Name the process by which these gases move into and out of the cell? A B Diffusion
- 10. 15/12/24 10 Osmosis Osmosis. . • OSMOSIS is a special kind of diffusion • It refers to the diffusion of WATER. • Water particles move from a region of HIGH water concentration to a region of LOW water concentration. • Through a partially permeable membrane. • This membrane allows water particles to pass through but stops large particles from passing through.
- 11. 15/12/24 11 Osmosis Osmosis • In animal and plant cells the cell membrane is a partially permeable membrane • Water will travel from a region of HIGH water concentration to a region of LOW water concentration until the concentrations are equal.
- 12. 15/12/24 12 Osmosis is the diffusion of water across a Osmosis is the diffusion of water across a partially permeable membrane partially permeable membrane Cell 1 Cell 2 Solute Solute Solute Solute Partially permeable membrane water
- 13. 15/12/24 13 Two visking tubing ‘cells’ have been set up as shown below: Experiment A has salt solution inside the Visking tubing and water outside Experiment B has water inside the Visking tubing and salt solution outside. WATER SALT SOLUTION
- 14. 15/12/24 14 • The Beakers will be examined after 30 minutes. • Describe what you expect to see in each beaker at the end of the experiment • A • B The tubing will get bigger and firmer because the water will enter the Visking tubing by osmosis. The water concentration outside the tubing is greater than that inside the tubing. The tubing will get smaller and floppy because the water will leave the Visking tubing by osmosis. The water concentration inside the tubing is greater than that outside the tubing.
- 15. The effect of osmosis on animal The effect of osmosis on animal cells cells • If there is a higher water concentration outside the cell water will move in until the concentrations are equal. If the concentration gradient is too high the cell will expand and possibly burst. • If there is a lower water concentration outside the cell water will move out until the concentrations are equal. If the concentration gradient is too high the cell will shrivel and no longer be able to carry out essential reactions. 15/12/24 15
- 16. The effect of osmosis on plant The effect of osmosis on plant cells cells • If there is a higher water concentration outside the plant cell water will move in to the cell until the concentrations are equal. The cell will not burst as the cell wall protects it. The cell will become turgid. • If there is a lower water concentration outside the plant cell water will move out of the cell until the concentrations are equal. If the concentration gradient is too high the cell membrane will move away from the cell wall (plasmolysis), the cell will become flaccid and the plant will wilt. 15/12/24 16
- 17. The effects of osmosis on a red The effects of osmosis on a red blood cell and a plant cell blood cell and a plant cell 15/12/24 17
- 18. 15/12/24 18 Which way will the water go? Which way will the water go? Pure Water Strong sugar solution Root hair cell Water in the soil 25% salt solution 50% salt solution 1% salt solution 0.1% salt solution Strong sugar solution Distilled water 50% sugar solution 50% sugar solution Partially permeable Membrane
- 19. Active Transport Active Transport • Active transport is a little like downfall. • Molecules are ‘grabbed’ and forced through a membrane. • Active transport moves against the concentration gradient.
- 20. Active Transport Active Transport • Active Transport is the movement of particles from a low concentration to a high concentration. • Active Transport requires energy to happen.