Question

End of exercise. Questions Name 1. In a perfectly tied and unbroken bag should we seeulence of sugar molecules passing throush the membrane"? Quallly your answer in terms of sectiva permeability operates. 2. From your graph of the Influence of temperature on the rate of osmosis, what can you conclude about the effects of temperature on the rate of osmosis Hint: How are temperature and molecular motion related? 3. Was dynamic equilibrium reached in any of the syrup demonstrations? Explain your answer. Hint: Did the graph for any of the treatments level off? 4. How did the differences in concentration affect the rate of osmosis? Why Is there a difference? 5. Why does a good cook wait to put the salad dressing on salad just before serving? Answer by explaining what happens to the cells in a lettuce leaf when the dressing is added. Hint, where does the water come from, the salad or the dressing? 6. Human cells contain 0.9% solutes (dissolved materials). Therefore, there is 99.1% water in these cells. The Pacific Ocean contains 3.56% salt. What percentage of the ocean is water? You are cast adrift on this ocean. What would happen to your cells if you were to drink the salt water? 7. Your younger brother just put your favorite saltwater fish into his freshwater aquarium. Predict what will happen to the fish, its cells, and your younger brother.

Answer 1

1. sugar molecules cannot pass through the membrane only solvent can pass through. Selective permeability defines the passage of particular solute through the membrane. this happens in may ways such as active, passive and facilitated diffusion.

2. Temperature directly affect the osmosis. increasing temperature increases the molecular movement of the solvent. so this increases the solvent diffusion.This is due to the increased diffusivity and reduced viscosity of solvent due to increased temperature.

3. In osmosis in general the system tries to attain the equilibrium until the concentration on both the side is equal.

4. osmosis is happening due the water potential. Pure water has higher potential than a solute. So always water tends to move towards the solution to attain equilibrium. So concentration plays a very important role in osmosis.

5. When a cell is put into a hypertonic solution(higher conc.than the cell), it tends to loose its water and shrink. this causes plamolysis. So if salad dressing is added earlier this may cause the lettuce leaf cells to shrink.

6. 100- 3.56 = 96.44% water will be there in pacific ocean. If we drink ocean water, our cells may tend to loose its water to dilute the concentrated solution into the gut (ocean water). This causes diarrhoea sometimes death due to dehydration.

7. In general salt water fish does not survive in fresh water due to osmotic imbalance in cells.