Presentation is loading. Please wait.

Presentation is loading. Please wait.

Boardworks GCSE Additional Science: Biology

Similar presentations


Presentation on theme: "Boardworks GCSE Additional Science: Biology"— Presentation transcript:

1 Boardworks GCSE Additional Science: Biology
Osmosis Osmosis

2 Boardworks GCSE Additional Science: Biology
Osmosis

3 Boardworks GCSE Additional Science: Biology
What is osmosis? Boardworks GCSE Additional Science: Biology Osmosis Osmosis is the diffusion of water molecules from a low concentration solution to a high concentration solution across a partially-permeable membrane. A partially-permeable membrane has holes in it that permit water molecules through, but are too small to allow larger molecules through. Osmosis can be demonstrated using visking tubing filled with a solution and placed in a beaker of pure water. partially- permeable membrane (visking tubing) The content on this slide is higher tier for OCR 21st Century GCSE Additional Science and OCR Gateway GCSE Additional Science. water glucose

4 Dilute vs. concentrated
Boardworks GCSE Additional Science: Biology Osmosis During osmosis, water molecules diffuse from pure water or dilute solution to more concentrated solutions. Dilute solutions have a high concentration of water molecules. Concentrated solutions have a low concentration of water molecules. pure water dilute solution concentrated solution

5 Boardworks GCSE Additional Science: Biology
Predicting osmosis Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This drag and drop activity provides the opportunity for informal assessment of students’ understanding of osmosis. The content in this activity is higher tier for OCR Gateway GCSE Additional Science.

6 Boardworks GCSE Additional Science: Biology
Osmosis in action Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This activity could be used as a starter exercise to work on osmosis.

7 Boardworks GCSE Additional Science: Biology
Osmosis and cells Boardworks GCSE Additional Science: Biology Osmosis Plant and animal cells are surrounded by a partially-permeable plasma membrane. This allows water and other small molecules to diffuse across. Plant cells additionally have a strong cell wall surrounding the membrane which offers support and protection. plasma membrane cell wall red blood cell plant cell

8 Osmosis and plant cells
Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This activity could be used to check students’ understanding of the effects of osmosis on plant cells.

9 Boardworks GCSE Additional Science: Biology
Osmosis and plants Boardworks GCSE Additional Science: Biology Osmosis Root cells in plants absorb water through osmosis. Many fine root hairs increase the surface area of a plant’s roots, allowing them to draw in more water from the surrounding soil. The information on this slide is higher tier for OCR 21st Century GCSE Additional Science. The presence of water in plant cells gives the plant structural support

10 Osmosis and animal cells
Boardworks GCSE Additional Science: Biology Osmosis Animal cells do not have a cell wall. This means they respond differently to plant cells to the gain and loss of water. In dilute solutions, osmosis can cause animals cells, such as red blood cells, to swell up and burst. This is called lysis. In concentrated solutions, water loss causes the cells to shrink. When this happens to red blood cells, it is called crenation.

11 Osmosis and animal cells
Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This activity could be used to check students’ understanding of the effects of osmosis on red blood cells.

12 Osmosis and animal cells
Boardworks GCSE Additional Science: Biology Osmosis In order to remain healthy, animal cells need to maintain an isotonic water balance. This means that the water concentration both inside and outside the cell is equal. hypothalamus The concentration of water and salt in the blood is controlled by the kidneys. The kidneys are controlled by the portion of the brain called the hypothalamus.

13 Boardworks GCSE Additional Science: Biology
Osmosis The worksheet ‘Diffusion, Osmosis and Active Transport’ accompanies this presentation.

14 Boardworks GCSE Additional Science: Biology
Glossary Boardworks GCSE Additional Science: Biology Osmosis Teacher notes crenation – The shrinking of animal cells in response to water loss by osmosis. diffusion – The movement of molecules from an area of high concentration to low concentration. isotonic – The state in which the water concentration on either side of a partially-permeable membrane is equal. lysis – The bursting of animal cells in response to water gain by osmosis. osmosis – The diffusion of water molecules from a dilute solution to a more concentrated solution. partially-permeable membrane – A membrane that allows only certain sized molecules to pass through it. plasmolysed – The state caused by water loss in plants, in which the cytoplasm pulls away from the cell wall. turgid – The state caused by high water uptake in plant cells.

15 Boardworks GCSE Additional Science: Biology
Anagrams Boardworks GCSE Additional Science: Biology Osmosis

16 Boardworks GCSE Additional Science: Biology
Which process? Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This completing sentences activity could be used as a plenary or revision exercise on movement in and out of cells. Students could be asked to write down the missing words in their books and the activity could be concluded by the completion on the IWB.

17 Boardworks GCSE Additional Science: Biology
Multiple-choice quiz Boardworks GCSE Additional Science: Biology Osmosis Teacher notes This multiple-choice quiz could be used as a plenary activity to assess students’ understanding of osmosis. The questions can be skipped through without answering by pressing the forward arrow. Students could be asked to complete the questions in their books and the activity could be concluded by the completion on the IWB.


Download ppt "Boardworks GCSE Additional Science: Biology"

Similar presentations


Ads by Google