Procedures This experiment consisted of three types of testing of diffusion

Procedures this experiment consisted of three types

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microscope hoping to see a cytoplasm no longer against the cell wall. Procedures This experiment consisted of three types of testing of diffusion, osmosis, and plasmolysis. First procedure observed diffusion across a differentially permeable membrane. One had gathered the necessary equipment needed, which was four dialysis clips, two pieces of water-soaked dialysis bags, small graduated cylinder and two beakers. First, the two dialysis bags were each folded at one end and then sealed tightly with a dialysis clip. Then, using the graduated cylinder, it was filled up with 5 mL of water and had gotten a pipet and transferred the water into the dialysis bag. Three drops of phenolphthalein were then added to the same dialysis bag and then the other end was then sealed securely with a dialysis clip. The outside of the bag was then rinsed under the sink. Then, a beaker was filled with 200 mL of tap water and then added 10 drops of 1 M sodium hydroxide (NaOH). The dialysis bag with the phenolphthalein was then submerged into the beaker. Using the graduated cylinder, one measured 5 mL of starch suspension in it and then using another pipet the 5 mL was added to the other dialysis bag. The
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Running Head: EXERCISE 9 - DIFFUSION AND OSMOSIS outside of the bag was then also rinsed under the sink. The other beaker not used, was then filled with 200 mL of tap water and instead of the sodium hydroxide, 40 drops of iodine was added to the beaker. The dialysis bag containing the starch was then submerged into the beaker. Finally, one had observed and recorded the color inside and outside the bags. The next procedure was to observe osmosis across a concentration gradient. Four pieces of water- soaked dialysis bags, eight dialysis clips, two beakers, and a scale was gathered for this test. The four bags were labeled from A-D, and each were sealed at one end with a dialysis clip. The instructor had already prepared the solutions that contained 1%, 10%, and 20% sucrose in them. In bag A, 10 mL of 1% sucrose was added in to it, was sealed tightly with a dialysis clip. 10 mL of 1% sucrose was added to bag B and sealed tightly with a dialysis clip. In bag C, 10 mL of 10% sucrose was added and then sealed tightly with a dialysis clip. Then, 10 mL of 20% sucrose was added to bag D and sealed tightly with a dialysis clip. Each of the four bags was then weighed and their initial mass was then recorded. The first beaker was then filled with 150 mL of 10% sucrose, and bag A was then placed into the beaker. The second beaker was filled with 1% sucrose and bags B, C, and D were then placed into it. Then, had to wait 15 minutes. After the 15 minutes, each bag was then removed from the beakers, dried, and then weighed. The mass was then recorded, and the change in weight was calculated. The four bags were then placed into the correct beakers, and waited another 15 minutes. After another 15 minutes, the bags were then again removed, dried and then were weighed. Mass of each were recorded, and change in weight was calculated. For one last 15-min interval, the bags were then put back into their right beakers. Repeated, each bag was taken out of the beakers, dried, and weighed. Mass
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  • Spring '14
  • AmyK.Wagner
  • Osmosis, Semipermeable membrane, bag

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