Investigating The Diffusion Of Water Molecules From An Area Of Low Water Potential

1051 WordsOct 23, 20145 Pages
Osmotic Diffusion across Semi-Permeable Membranes to Support Water Potential Flowing from an Area of High Water Potential to an Area of Low Water Potential By Ruth Slade BZ 120 LAB #10 Introduction: Understanding the diffusion of water into and out of the cell through osmosis is fundamental to the learning and teaching of biology (e.g. Cook, Carter and Wiebe, 2008). In the following paper will attempt to prove a hypothesis that osmosis or water potential can be observed to “flow” through a semi-permeable membrane from high water potential to areas of low water potential. The hypothesis will use sucrose bags in various medias with a control bags that will gain or lose water weight. Objective: To observe diffusion of water…show more content…
Bag #4 had a 40% solution of sucrose and was red. Bag #5 was half filled with pure water with no coloring. Bags 1-5, where all half full with the described solutions, then tied close. Also, another two bags (bag #6 and #7), one containing water (bag #7) and bag #6 with 40% sucrose solution with red food coloring, are completely filled when tied, unlike bags #1-5. The dialysis tubes where knotted at both ends with a simple knot and tested to ensure no leaks, then a 6 inch long string was tied to one end of the bags to aid in retrieval from the beakers. One beaker was filled with enough water to cover all 5 half full bags (bags 1-5), whereas the other was filled with enough 40% sucrose solution to emerge the 2 full bags (bags 6 & 7). Please note that a control bag was present in both beakers, bag #5 in Beaker with water and bag #7 in the Beaker with 40% sucrose solution. At the beginning of the experiment all packets where weighed and recording in grams on the scale, all bags where then placed into their respective beakers. They were weighed at 15 minute intervals, for a total of 60 minutes. Upon weighing all the packets where rinsed and dried thoroughly to prevent any additional solution or water to cling to the exterior of the bags, the results were recorded in Figure 1. Results: After 60 minutes, in the Beaker with water and bags 1-5 weights and % changes are as follows. Bag 1 with 5% sucrose gained the least with 0.4
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