Osmosis Lab

Osmosis Lab March 22, 2013 Amanda L***** Introduction Transport into and out of your cells is important because without cellular transport, the cell could not move material into or out of the cell. This would lead to its inability to survive because cells must take in oxygen and food, and expel waste material that could inhibit the cell from performing in the body. A type of cell transport in particular is passive transport.Passive transport is a kind of  transport  by which  ions  or  molecules  move along a  concentration gradient, which means movement  from an area of  higher  concentration  to an area of  lower  concentration. Passive transport does not require an output of energy. There are 4 main types of passive transport: simple diffusion, facilitated diffusion, filtration, and osmosis. In this lab, we are particularly looking at osmosis and how it affects plant and animal cells.Osmosis is the diffusion of water molecules across a selectively permeab le membrane. In part A of this lab, we submerged the eggs in vinegar overnight, followed by peeling the softened shells from the eggs carefully while trying not to break the membrane the next day. We then recorded any observations we made on the eggs including weight and appearance. Next, we recorded any observations we could make on the carrots and potatoes before we put them into their solution.We then placed the eggs(animal cells), carrots, and potatoes(plant cells) into their solutions and let them stand in their hypotonic and hypertonic solutions overnight followed by observing any changes in weight and appearance the next day. In Part B, we observed an onion cell exposed to distilled water under a microscope, and another onion cell exposed to a saturated salt solution, and drew the two different cells comparing the differences between their exposure to the hypotonic(water) and hypertonic(salt water, corn syrup) solutions. Part APurpose To observe the effects of hypotonic and h ypertonic solutions on plant and animal cells. Hypothesis I predict that the hypotonic solution will cause the plant and animal cells to enlarge due to the difference in concentration on the inside of the cells, and the hypertonic solutions will cause the cells to shrink due to absorption of water molecules in the cells. Materials * 400mL beakers (2) * Tap Water * Eggs (2) * Vinegar * Salt water * Carrots (2) * Corn syrup * Potato strips (2) Procedure Day 1 1. Submerge the eggs in vinegar in a beaker. May have to weigh them down) 2. Leave them undisturbed overnight. Day 2 3. Peel the softened shells from the egg carefully so as not to break the 3membrane. 4. Record any pertinent observations on the egg, carrot and potato strip. 5. Place one egg and carrot in a beaker of water. 6. Place potato strip in a test tube. 7. Place the carrot in a beaker of saturated salt water and use corn syrup for the other egg. 8. Place the second potato strip in a test tube of saturated salt water. 9. L abel the beakers and test tube and place in the cupboard overnight.Day 3 10. Record any pertinent observations. Observations Plant and Animal Cells in Hypertonic Solution: | Solution| Appearance/texture Before| Weight before(g)| Appearance/texture After| Weight After(g)| Egg 1 | Corn Syrup| -translucent-yellowish colour-soft | 77. 53| -opaque-white/yellow colour-feels firm| 51. 17| | | | | | | Carrot 1| Salt solution| -orange-sturdy| 2. 59| -orange-sturdier -appears slightly smaller| 2. 36| | | | | | | Potato 1| Salt solution| -yellowish colour-sturdy| 2. 92| -same colour-sturdier | 2. 85| | | | | | |Plant and Animal Cells in Hypotonic Solution(Distilled Water): | Weight Before(g)| Appearance/Texture After | Weight After (g)| Egg 2| 71. 82| -opaque-orange colour| 84. 10| Carrot 2| 2. 29| -orange colour-not as sturdy| 2. 52| Potato 2 | 2. 49| -yellowish colour-not as sturdy| 2. 98| Part B Purpose To observe changes in plant cells when they are placed in a hypotonic(distilled water) s olution and a hypertonic(saturated salt water) solution. Hypothesis I predict that the hypertonic solution will cause the water to leave the cell, shrinking it due to dehydration from the salt.Materials * Microscope * Microscope slide * Coverslip * Tap water * Saturated salt water * Onion Procedure 1. Prepare a wet mount using distilled water of a thin section of onion skin on a microscope slide. 2. View to draw one to two cells. Use magnification which shows the best detail. 3. Prepare another wet mount using the saturated salt solution instead of distilled water. 4. View and draw one to two cells. Use the same magnification you used for the first drawing. Observations Refer to onion cell drawings. AnalysisMy predictions were both correct in part A and in part B when I stated that the cells would shrink in the hypertonic solution and enlarge in the hypotonic solution. The reason this occurred was because when a cell is immersed into a hypertonic solution, the tendency is for water to flow out of the cell in order to balance the concentration of the solute. When a cell is immersed in a hypotonic solution, it has a tendency to balance concentrations by water flowing into the cell, causing it to enlarge because of the lower concentration of solutes in its surroundings.None of the cells observed had the same weight when removed from their solution meaning they were not isotonic. Had they been isotonic, the solution would have no effect on the cells, therefore when placed in an isotonic solution the cells would tend to neither gain nor lose water. When observing the effects of hypotonic and hypertonic solutions on plant and animal cells, I came to the conclusion that the plant cells did not change much in weight. This is due to their cell walls which make it tougher for the cell to expand.The pressure exerted by water inside the cell against the cell wall is known as turgor pressure. In the drawing of the onion cell exposed to a hypertonic solution, the cell membr ane appeared to be shriveled up inside the cell wall due to its turgidity. Evaluation In part A, I did not experience any errors with the cells themselves, but potential sources of error could have been inaccurate measurements before and after placing the cells in their solution. Other potential sources of error could have occurred while peeling the shell off the egg, causing the membrane to break.In part B, I added too much distilled water to the slide making it difficult to get a good view of the onion cell exposed to the hypotonic solution. When performing a similar experiment in the future, I will be sure to add less drops with the eyedropper to the slide, enabling a clearer view of the cells I am observing. Application Questions 1. If the cells of a fresh water plant are placed in salt water, they will shrivel up due to the concentration difference between the salt water and the contents of the cell (cytoplasm). The water would escape the cell through osmosis causing it to dehy drate resulting in the shrinkage of the plant cell. . The fish that is used to salt water has high solutes and the freshwater is deficient of solutes, so when you place a  saltwater fish  in freshwater, the freshwater will move into the cells, causing them to swell and burst. 3. Grocery stores frequently spray the vegetables because the fresh water enters the plant cells through osmosis and makes them more turgid resulting in longer lasting freshness. 4. The use of road salt in the winter kills the plants alongside the road because the salt causes the cell to enter a hypertonic state. This causes the cytoplasm to move away from cell wall eventually making the plant shrivel up and die. Osmosis Lab Osmosis Lab March 22, 2013 Amanda L***** Introduction Transport into and out of your cells is important because without cellular transport, the cell could not move material into or out of the cell. This would lead to its inability to survive because cells must take in oxygen and food, and expel waste material that could inhibit the cell from performing in the body. A type of cell transport in particular is passive transport.Passive transport is a kind of  transport  by which  ions  or  molecules  move along a  concentration gradient, which means movement  from an area of  higher  concentration  to an area of  lower  concentration. Passive transport does not require an output of energy. There are 4 main types of passive transport: simple diffusion, facilitated diffusion, filtration, and osmosis. In this lab, we are particularly looking at osmosis and how it affects plant and animal cells.Osmosis is the diffusion of water molecules across a selectively permeab le membrane. In part A of this lab, we submerged the eggs in vinegar overnight, followed by peeling the softened shells from the eggs carefully while trying not to break the membrane the next day. We then recorded any observations we made on the eggs including weight and appearance. Next, we recorded any observations we could make on the carrots and potatoes before we put them into their solution.We then placed the eggs(animal cells), carrots, and potatoes(plant cells) into their solutions and let them stand in their hypotonic and hypertonic solutions overnight followed by observing any changes in weight and appearance the next day. In Part B, we observed an onion cell exposed to distilled water under a microscope, and another onion cell exposed to a saturated salt solution, and drew the two different cells comparing the differences between their exposure to the hypotonic(water) and hypertonic(salt water, corn syrup) solutions. Part APurpose To observe the effects of hypotonic and h ypertonic solutions on plant and animal cells. Hypothesis I predict that the hypotonic solution will cause the plant and animal cells to enlarge due to the difference in concentration on the inside of the cells, and the hypertonic solutions will cause the cells to shrink due to absorption of water molecules in the cells. Materials * 400mL beakers (2) * Tap Water * Eggs (2) * Vinegar * Salt water * Carrots (2) * Corn syrup * Potato strips (2) Procedure Day 1 1. Submerge the eggs in vinegar in a beaker. May have to weigh them down) 2. Leave them undisturbed overnight. Day 2 3. Peel the softened shells from the egg carefully so as not to break the 3membrane. 4. Record any pertinent observations on the egg, carrot and potato strip. 5. Place one egg and carrot in a beaker of water. 6. Place potato strip in a test tube. 7. Place the carrot in a beaker of saturated salt water and use corn syrup for the other egg. 8. Place the second potato strip in a test tube of saturated salt water. 9. L abel the beakers and test tube and place in the cupboard overnight.Day 3 10. Record any pertinent observations. Observations Plant and Animal Cells in Hypertonic Solution: | Solution| Appearance/texture Before| Weight before(g)| Appearance/texture After| Weight After(g)| Egg 1 | Corn Syrup| -translucent-yellowish colour-soft | 77. 53| -opaque-white/yellow colour-feels firm| 51. 17| | | | | | | Carrot 1| Salt solution| -orange-sturdy| 2. 59| -orange-sturdier -appears slightly smaller| 2. 36| | | | | | | Potato 1| Salt solution| -yellowish colour-sturdy| 2. 92| -same colour-sturdier | 2. 85| | | | | | |Plant and Animal Cells in Hypotonic Solution(Distilled Water): | Weight Before(g)| Appearance/Texture After | Weight After (g)| Egg 2| 71. 82| -opaque-orange colour| 84. 10| Carrot 2| 2. 29| -orange colour-not as sturdy| 2. 52| Potato 2 | 2. 49| -yellowish colour-not as sturdy| 2. 98| Part B Purpose To observe changes in plant cells when they are placed in a hypotonic(distilled water) s olution and a hypertonic(saturated salt water) solution. Hypothesis I predict that the hypertonic solution will cause the water to leave the cell, shrinking it due to dehydration from the salt.Materials * Microscope * Microscope slide * Coverslip * Tap water * Saturated salt water * Onion Procedure 1. Prepare a wet mount using distilled water of a thin section of onion skin on a microscope slide. 2. View to draw one to two cells. Use magnification which shows the best detail. 3. Prepare another wet mount using the saturated salt solution instead of distilled water. 4. View and draw one to two cells. Use the same magnification you used for the first drawing. Observations Refer to onion cell drawings. AnalysisMy predictions were both correct in part A and in part B when I stated that the cells would shrink in the hypertonic solution and enlarge in the hypotonic solution. The reason this occurred was because when a cell is immersed into a hypertonic solution, the tendency is for water to flow out of the cell in order to balance the concentration of the solute. When a cell is immersed in a hypotonic solution, it has a tendency to balance concentrations by water flowing into the cell, causing it to enlarge because of the lower concentration of solutes in its surroundings.None of the cells observed had the same weight when removed from their solution meaning they were not isotonic. Had they been isotonic, the solution would have no effect on the cells, therefore when placed in an isotonic solution the cells would tend to neither gain nor lose water. When observing the effects of hypotonic and hypertonic solutions on plant and animal cells, I came to the conclusion that the plant cells did not change much in weight. This is due to their cell walls which make it tougher for the cell to expand.The pressure exerted by water inside the cell against the cell wall is known as turgor pressure. In the drawing of the onion cell exposed to a hypertonic solution, the cell membr ane appeared to be shriveled up inside the cell wall due to its turgidity. Evaluation In part A, I did not experience any errors with the cells themselves, but potential sources of error could have been inaccurate measurements before and after placing the cells in their solution. Other potential sources of error could have occurred while peeling the shell off the egg, causing the membrane to break.In part B, I added too much distilled water to the slide making it difficult to get a good view of the onion cell exposed to the hypotonic solution. When performing a similar experiment in the future, I will be sure to add less drops with the eyedropper to the slide, enabling a clearer view of the cells I am observing. Application Questions 1. If the cells of a fresh water plant are placed in salt water, they will shrivel up due to the concentration difference between the salt water and the contents of the cell (cytoplasm). The water would escape the cell through osmosis causing it to dehy drate resulting in the shrinkage of the plant cell. . The fish that is used to salt water has high solutes and the freshwater is deficient of solutes, so when you place a  saltwater fish  in freshwater, the freshwater will move into the cells, causing them to swell and burst. 3. Grocery stores frequently spray the vegetables because the fresh water enters the plant cells through osmosis and makes them more turgid resulting in longer lasting freshness. 4. The use of road salt in the winter kills the plants alongside the road because the salt causes the cell to enter a hypertonic state. This causes the cytoplasm to move away from cell wall eventually making the plant shrivel up and die. Osmosis Lab Name: ____Justine Basilone___ Osmotic Regulation Virtual Laboratory Biology Go to the following virtual laboratory: http://www. glencoe. com/sites/common_assets/science/virtual_labs/LS03/LS03. html Answer your questions in this word document, save the file and submit through Edmodo. Your answers should be at least 2 complete sentences if not more! Part I: Observations & Data: Read the Introductory information and the Procedure located in the window to the left of the screen and then perform the laboratory. For your convenience, the data table has been inserted below – fill this one in (the website tends to delete data): Molecules Name |Red Blood Cell: |Red Blood Cell: | | |Net Water Movement In / Out |Appearance of Cell | |Hypotonic Solution | |Blown up and fat | | |Moves in to red blood cell | | |Isotonic Solution | |Normal, did not appear different | | |Moves in and out of red blood cell | | |Hypertonic Solution | |Shriveled up | | |Moves out of red blood cell | | | Elodea: |Elodea: | | |Net Water Movement In / Out |Appearance of Cell | |Hypotonic Solution | |Gets bigger | | |Moves in to Elodea | | |Isotonic Solution | |Appears the same. | |Moves in and out of Elodea (stays the same) | | |Hypertonic Solution |Moves out of Elodea |The inside shrinks and gets smaller | | |Paramecium: |Paramecium: | | |Net Water Movement In / Out |Appearance of Cell | |Hypotonic Solution | |Paramecium blows up and gets bigger. | |Moves in to Paramecium | | |Isotonic Solution | |Seems to stay the same. | | |Moves in and out of Paramecium | | |Hypertonic Solution | |Shriveled up and makes the cell appear smaller. | | |Moves out of Paramecium | | Part II: Questions & Conclusions: 1) Did water move into the cells or out of the cells while they were surrounded by hypotonic solution?Water moved into all of the cells while they were surrounded by hypotonic solution. 2) In which direction did the water move through the cell membrane when the cells were surrounded by the hypertoni c solution? The direction that the water appeared to be moving through the cell membrane was both ways, in and out. 3) Compare and contrast what happens to an animal cell, a plant cell, and a Paramecium cell in a hypotonic, and isotonic, and a hypertonic solution. (Does the cell wall make a difference? ) What seemed to surprise me most is that no matter what cell was used each solution had the same effect of the cells, no matter what kind it was. So no, the cell wall does not appear to make a difference. ) Could Elodea or Paramecium from a freshwater lake be expected to survive if transplanted into the ocean? Explain. Since they both react the same to different solutions I do believe that it is possible for both cells to be transplanted in the ocean and survive. 5) If you were to grill a steak, would it be better to put salt on it BEFORE or AFTER you cooked it? Explain why, USING THE TERMS OF OSMOSIS from this activity. While grilling a steak it is better to put salt on it before yo u grill it so while it is grilling osmosis will occur and it will retain the salt. So instead of it just sitting on top of the steak it will be on the inside. Giving it more flavor of the salt while eating it. ) Why does salad become soggy and wilted when the dressing has been on it for a while? Explain why, in terms of osmosis. The reason why salad becomes soggy and wilted when dressing has been on it for a while is because as it is sitting there osmosis takes place and the salad begins to take in the moisture of the salad dressing, leaving it soggy and wilted. 7) An effective way to kill weeds is to pour salt water on the ground around the plants. Explain why the weeds die, using the principles discovered in this virtual lab. I believe that the weeds would die due to the fact that as the weeds take in what they think is just water only to later dry out by taking in the salt along with it using osmosis.