Diffusion Experiment: Osmosis in Sucrose Solutions

The purpose of this study is to see the effects of diffusion through a selectively permeable membrane when placed in a sucrose solution. This experiment is a model of how diffusion takes place. The dialysis tubing serves as the permeable membrane with which diffusion will occur. Since cells are so small in size, this experiment poses as a model in which diffusion can be witnessed and recorded. I hypothesize that the more concentrated sucrose solutions will cause a greater amount of osmosis.

To being the experiment each dialysis tubing was tied off at the bottom and filled with a sucrose solution. Bag A and Bag B were both filled with a 10mL 1% sucrose solution. Bag C was filled with a 10mL 25% sucrose solution and Bag D was filled with a 10mL 50% sucrose solution. Each bag had all the air pushed out of it and the open end was tied off. Each bag was also label with a piece of tape attached to a piece of dental floss marking each individual bag so as not to confuse them. The bags were then weighed and the weight was written down. After that Bag A was placed in a 50% sucrose solution and Bags B, C and D were all placed in a 1% sucrose solution. Once all the bags were placed in their respected solutions, the weight changes were recorded in fifteen minute intervals from the initial starting time and weight change was recorded.

When the experiment was done, Bag A was the only bag to have a drastic weight decrease. Bag A’s initial weight was 11.2 grams and in the end had a weight of 5.9 grams after the full sixty minutes. Bag B had a slight loss in weight, from its initial weight of 11.8 grams to 11.2 grams. On the other hand, Bags C and D each gained weight over time with Bag C starting out with 11.8 grams and ending at 13.5 grams. Bag D’s weight began at 13.2 grams and finished up at 17.5 grams. The charts representing the changes can be found attached at the end of this report.

From the results taken, the more concentrated solutions of sucrose seemed to draw the water towards it. This supports my hypothesis and also shows that sucrose is also a hypertonic solution since it there was more water brought into the solution than outside of it. Bag A had a stronger concentration outside its membrane which caused the sucrose on the outside to draw the water out of the dialysis tubing and into the solution that was in the bowl. Bag D has the greatest weight in the end primarily due to the fact that it also contained the highest percentage of solution within the membrane. Bag B had little change in weight due to the low concentration of sucrose in the bag and in the solution outside the bag. Since Bags C and D had the higher concentrations they pull the majority of the water out of the solution and into their membranes. Had Bag B been placed in the solution that Bag A was in, it would more than likely have the same affect that Bag A had.

This could be applied in the real world with people who suffer from dehydration. By raising the sugar levels in their body, they are more likely to take in more water into their cells. One thing that could be tried in future experiments could be to add additional types of solutions to the experiment that would simulate more of the human internal cell system. By adding more substances, the chances of seeing how osmosis truly works in the body can be seen.

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