Post Lab Questions
1) Did the glucose molecules diffuse through the dialysis tubing filled with starch-glucose solution ? How do you know this is true? Why did this occur? (Hint: make a claim, give evidence, and reasoning)
2) Did the starch molecules diffuse through the dialysis tubing filled with starch-glucose solution ? How do you know this is true? Why did this occur? (Hint: make a claim, give evidence, and reasoning)
3) Think about the results for the dialysis tube that contained starch-glucose solution with amylase (Teacher demo/video) . What would happen to the starch in the dialysis tubing? How do you know? How could you test it?
Explain. (Hint: make a claim, give evidence, and reasoning for the following)
4) What would happen if the concentration of the glucose in the starch-glucose solution was higher or lower?
5) What would happen if the concentration of the starch in the starch-glucose solution was higher or lower?
6) Explain how the dialysis tubing was selectively permeable.
7) Put the following in order from smallest to largest using what you observed from this lab experiment.
- starch, Lugol’s Iodine (iodine potassium iodide), glucose, Dialysis membrane pores, water
8) Would there be a change in mass if we had the same solution in the dialysis tubing and in the beaker.
9) Explain what would happen if we put water in the dialysis tubing and placed it in a beaker of starch-glucose solution.
10) What are some experimental flaws or sources of error in the experiment and how it was set up? How did these flaws affect the data? How could these flaws be corrected if we did this experiment again?
11) What were some problems you encountered during the experiment? How could you avoid these problems in the future?
12) How does all of this relate to the real world? To find out, research and explain one of the following applications (Find out what it is, Explain why it happens, Explain how it relates to what you learned in this lab and in class)
Osmotic dehydration
Reverse osmosis
Medical storage of red blood cells for transfusions
Water absorption in plants
How people can die from drinking too much water
Diffusion Lab Report Format
Title:
Purpose:
Abstract:
An abstract is a concise one paragraph summary of the entire lab activity or experiment (not more than 10 sentences long).
The following must be included in your abstract
Why was the laboratory activity or experiment conducted?
What did you do?
What were the results?
What conclusions can be made?
Data/Observations:
Conclusion:
• Experimental Analysis : Why the data came out as it did and what does it all mean?
Use the CLAIM, EVIDENCE, REASONING format for each of the following:
For the Starch + Glucose Experiment
Glucose Diffusion Results ( (post lab Q #1 -
For the Starch + Glucose + Amylase Experiment
1 paragraph)
Starch Diffusion Results ( (post lab Q #2 - 1 paragraph)
Starch Diffusion Results – What happened to the starch in the tubing? ( post lab Q #3 - 1 paragraph)
• Evaluation of the experimental design (post lab Q #10)
What were potential flaws in the experiment? [Not things due to human error!]
How could these flaws have affected the data?
How can these flaws be corrected?
• Application of the lab and related concepts to real world situations (post lab Q #12)
Example from class: Sports Drinks (such as Gatorade) Do not use this example
Research and explain one of the following applications (Find out what it is, Explain why it happens,
Explain how it relates to what you learned in this lab and in class)
Osmotic dehydration
Reverse osmosis
Medical storage of red blood cells for transfusions
Water absorption in plants
How people can die from drinking too much water
Sources: Cite the sources you used for your application section