Osmosis
Contents
Key Stage 4
Meaning
Osmosis is the diffusion of water from a high water concentration to a low water concentration through a partially permeable membrane.
About Osmosis
- Osmosis is how plants get water through their roots and how animals gain water through the walls of the Small Intestine and Large Intestine.
- Osmosis is how cells absorb and release water.
- Osmosis is a passive process which means it does not require energy to take place.
- A high water concentration means water with very little dissolved salts or sugars. A low water concentration is water with a high concentration of salts or sugars in solution.
- A partially permeable membrane is a membrane which only allows through certain molecules. This is often small molecules like water that can pass through but not larger molecules like sugar. However, the cell membrane is selectively permeable which means it can control which molecules pass through.
NB: Water Concentration may be referred to as 'Water Potential' in some textbooks.
References
AQA
- Osmosis, page 18, GCSE Combined Science; The Revision Guide, CGP, AQA
- Osmosis, page 21, GCSE Biology; The Revision Guide, CGP, AQA
- Osmosis, pages 16-19, GCSE Biology; Third Edition, Oxford University Press, AQA
- Osmosis, pages 33-5, GCSE Biology, Hodder, AQA
- Osmosis, pages 33-5, GCSE Combined Science Trilogy 1, Hodder, AQA
- Osmosis, pages 48, 49, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Osmosis, pages 54, 55, GCSE Biology, CGP, AQA
- Osmosis, pages 88-91, 92, 108-9, 198, GCSE Biology; Student Book, Collins, AQA
- Osmosis; investigating, pages 49, 50, GCSE Combined Science Trilogy; Biology, CGP, AQA
- Osmosis; investigating, pages 55, 56, GCSE Biology, CGP, AQA
- Osmosis; investigation of, page 41, GCSE Combined Science Trilogy 1, Hodder, AQA
Edexcel
- Osmosis, page 21, GCSE Biology; The Revision Guide, CGP, Edexcel
- Osmosis, pages 18, 19, GCSE Combined Science; The Revision Guide, CGP, Edexcel
- Osmosis, pages 24-25, GCSE Biology, Pearson, Edexcel
- Osmosis, pages 49, 50, GCSE Biology, CGP, Edexcel
- Osmosis; investigating, page 22, GCSE Biology; The Revision Guide, CGP, Edexcel
- Osmosis; investigating, pages 52-54, GCSE Biology, CGP, Edexcel
OCR
- Osmosis, page 26, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
- Osmosis, pages 31-33, Gateway GCSE Biology; The Revision Guide, CGP, OCR
- Osmosis, pages 60-61, 80, 124-125, 264-265, Gateway GCSE Biology, Oxford, OCR
- Osmosis; experiments, page 32, Gateway GCSE Biology; The Revision Guide, CGP, OCR