BIOLOGY HOMEWORK
JRAE79
cell_membrane_lab_report_assignment.pdf.docxCell Membranes and Transport
Hands-on labs, inc. Version 42-0033-00-01
LAB REPORT
PHOTOS – Include the digital photos as attachments or place them right into your report.
Photo #1 - Take a photo of the results from the osmosis experiment, by placing the 3 bags (after drying the outside) on a piece of white paper as background. Write HOT, COLD, AMBIENT underneath each bag. Get close enough to see the different colors. This photo is after 30 min. (not 60)
Photo #2 – Take a photo of the row of test tubes with the potato strips in them along with the solutions.
Photo #3 - After 24 hours have elapsed for the potato/sucrose experiment, hold tubes A and B up side by side and take a photo close enough that you can see the difference in the potato7 strips inside.
Exercise 1: Diffusion
Observations
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Data Table 1: Rate of diffusion in different temperatures |
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ºC |
Minutes |
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Temperature |
Initial Temp. |
Initial Color |
5 |
10 |
15 |
20 |
25 |
30 |
60 |
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Cold |
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Ambient |
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Hot |
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Experiment
Cell MeMbranes and TransporT
187
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Questions
A. Write a one-paragraph analysis of the results for the procedure. Provide reasons for the
differences in the rates of diffusion at the different temperatures.
B. Did the sizes of the molecules affect their movement?
C. What molecules remained inside the bags? How can you make this determination? What molecules were able to freely move into the bags?
Exercise 2: osmosis
Observations
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DataTable 2: Potato Mass |
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Contents in Test Tube |
Initial Mass of Two Potato Strips |
Final Mass of Two Strips |
Mass Difference |
% Change in Mass |
Class Average Percent Change in Mass (if available) |
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a) Distilled Water |
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b) 1.0 M Sucrose |
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c) 0.8 M Sucrose |
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d) 0.6 M Sucrose |
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e) 0.4 M Sucrose |
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f) 0.2 M Sucrose |
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Questions
A. Describe how the potato cylinders changed in their turgidity. Identify which of the solutions were isotonic, hypertonic, and hypotonic in relation to the potato.
B. What would happen to a red blood cell placed in distilled water? Why?
