3 5 potatoes 4 inches or more long sharp knife

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3-5 potatoes (4 inches or more long) sharp knife cutting board ruler with metric units: cm, mm Tables 1 and 2 to record data, see below . BIO 101 Lab 05: Osmosis and Diffusion 7
Methods Note there are important differences in your method vs. the video, due to the items available in a home kitchen. Be certain follow the directions provided below. Step 1. Prepare salt solutions. 1. Label 6 glasses: #1 #2 #3 #4 #5 #6. 2. Make a stock salt solution . Add 2 Tbs of salt to 2C of water in a bowl and stir well to dissolve salt. This solution is ~ 8% salt. 3. Using a ladle, remove 1C of stock salt solution and pour into glass #6 , set aside. ~ 8% salt 4. In the bowl, add 1C tap water to remaining salt solution. Stir well. Ladle 1 C of this solution into glass #5 , set aside. ~ 4% salt 5. In bowl ,add 1C tap water to remaining salt solution. Stir well. Ladle 1 C of this solution into glass #4 , set aside. ~ 2% salt 6. In bowl, add 1C tap water to remaining salt solution. Stir well. Ladle 1 C of this solution into glass #3 , set aside. ~ 1% salt 7. In bowl add 1C tap water to remaining salt solution. Stir well. Ladle 1 C of solution into glass #2 , set aside. ~ 0.5% salt 8. Discard all of the remaining solution that is left in the original bowl of 8% salt solution. 9. Pour 1C of tap water into glass #1 , and set aside. ~0% salt Step 2. Prepare potatoes. Cut 18 strips of potatoes so that each one measures 0.5 cm x 0.5 cm x 6.0 cm. Measuring and cutting accurately is very important since the length of the potato strips is your data. Take a photo of 18 cut potato strips at the start (now) and another photo after soaking in salt solutions. Record the potato strip Texture Before Soaking in Table 1 , e.g. hard, firm, etc. Record Initial Length (cm) now, before soaking, in Table 2 . BIO 101 Lab 05: Osmosis and Diffusion 8
Step 3. Begin the experiment. Add 3 cut potato strips to each glass so they stand up vertically. Record the start time 3:32pm . Soak for 30 minutes. Since most students do not have a cork borer at home, 30 minutes incubation time minimizes error in cutting equal sized slices. Step 4. Gather data. At 30 minutes record the stop time 4:02pm . Remove the cut potato strips from each glass, keeping the strips separated by soaking solution. Gently blot dry with a paper towel. Take a 2 nd photo of the potato strips. Measure the length of each of the three potato strips, and record the Final Length (cm) to the nearest 1/10 of a cm (to the nearest mm) in Table 2 . Accurate measuring is critical! In Table 1 above, record the potato strip Texture After Soaking in Table 1 , e.g. hard, firm, flexible, soft, mushy, etc. BIO 101 Lab 05: Osmosis and Diffusion 9
Results: Data Tables Table 1. Glass 1 Glass 2 Glass 3 Glass 4 Glass 5 Glass 6 Salt % 0 0.5 % 1 % 2 % 4 % 8 % Texture Before Soaking Normal Normal Normal Normal Normal Normal Texture After Soaking Stiff and hard Still stiff but slightly bendy More bendy and slightly soft Bendy and soft Vey bendy and mushy Texture is very flexible and mushy Table 2.

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