BIO LABS
ladydi
44-0030-00-01_rpt_basic_chemistry_for_inves.pdf
Experiment Basic Chemistry for Investigating Living Systems
1 ©Hands-On Labs, Inc. www.HOLscience.com
Basic Chemistry for Investigating Living Systems
Margaret Vorndam, M.S. Version 42-0030-00-01
Lab Report Assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
Observations
Data Table 1: Biuret Reagent Test for (Student to fill in)
Test Tube
Contains
Hypothesis: Contains Protein Yes or No?
Final Color
Is test substance present/ absent?
1 Water
2 Albumen
3 Amylase
4 Potato Starch
5 Onion Juice
6 Potato Juice
Data Table 2: Iodine Solution Test for (Student to fill in) Test Tube
Contains
Hypothesis Contains Starch Yes or No?
Final Color
Is test substance present/ absent?
1 Water
2 Albumen
3 Amylase
4 Potato Starch
5 Onion Juice
6 Potato Juice
Experiment Basic Chemistry for Investigating Living Systems
2 ©Hands-On Labs, Inc. www.HOLscience.com
Data Table 3: Benedict’s Reagent Test for (Student to fill in)
Test Tube
Contains
Hypothesis Contains Sugar Yes or No?
Final Color
Is test substance present/ absent?
1 Water
2
Glucose
3 Albumen
4 Potato Starch
5 Onion
6 Potato Juice
Data Table 4: Lipid Test Results
Macromolecule Being Tested Hypothesis: Contains lipids, or
not? Results from Test
Potato Starch
Onion Juice
Vegetable Oil
Distilled Water
Albumen
Potato Juice
Data Table 5: Testing the Chemical Composition of Cells
Indicate a + mark if the reagent reacts with test substance. Indicate a - mark if the reagent does NOT react with test substance.
Test Substance Biuret Solution Iodine Stain Benedict’s Reagent Sudan III
Protein (Albumen)
Sugar
Starch
Lipid
Experiment Basic Chemistry for Investigating Living Systems
3 ©Hands-On Labs, Inc. www.HOLscience.com
Exercise 1: Testing for the Presence of Proteins in Cells Questions
A. What is the test substance?
B. Which test tube represents the control? Why?
C. Which test tube contained the most test substance?
D. Other than the control, which test tube contained the least test substance?
E. Did the results agree with your initial hypothesis in every case? Why or why not?
F. What are your conclusions about your results?
G. If the color change is not as you expected, what might be the reasons?
H. Add another 5 drops of Biuret Reagent to each test tube and stir as before. Do your results change?
Experiment Basic Chemistry for Investigating Living Systems
4 ©Hands-On Labs, Inc. www.HOLscience.com
Discussion
A. What is the purpose of this exercise?
B. Why is it important to clean droppers and equipment between chemical uses?
C. What other types of foods or substances contain high levels of protein?
D. Suggest a situation where you might use the Biuret Reagent colorimetric test.
E. What other types of analytical procedures detect the presence of proteins?
Exercise 2: Testing for the Presence of Starch in Cells Questions
A. What is the test substance?
B. Which test tube represents the control? Why?
C. Which test tube contained the most test substance?
D. Other than the control, which test tube contained the least test substance?
Experiment Basic Chemistry for Investigating Living Systems
5 ©Hands-On Labs, Inc. www.HOLscience.com
E. Did the results agree with your initial hypothesis in each case, why or why not?
F. What are your conclusions about the results?
G. If the color change is not as you expected it to be, what might be the reasons?
Discussion
A. What is the purpose of this exercise?
B. What other types of foods or substances contain high levels of starch?
C. Suggest a situation where you might use the iodine colorimetric test.
D. What other types of analytical procedures detect the presence of starch?
Exercise 3: Testing for the Presence of Sugar in Cells Questions
A. What is the test substance?
B. Which test tube represents the control? Why?
Experiment Basic Chemistry for Investigating Living Systems
6 ©Hands-On Labs, Inc. www.HOLscience.com
C. Which test tube contained the most test substance?
D. Besides the control, which test tube contained the least test substance?
E. Did the results agree with your initial hypothesis in every case? Why or why not?
F. What are you conclusions about the results?
G. If the color change is not as expected, what might be the reasons?
Discussion
A. What is the purpose of this exercise?
B. Suggest a scenario where you might use the Benedict’s reagent colorimetric test.
C. How might one determine whether the potato or onion contains more sugar?
D. What other types of foods or substances contain high levels of sugar?
E. What other types of analytical procedures detect the presence of sugars?
Experiment Basic Chemistry for Investigating Living Systems
7 ©Hands-On Labs, Inc. www.HOLscience.com
Exercise 4: Testing for the Presence of Lipids in Cells Questions
A. What is the test substance?
B. Which test tube represents the control?
C. Which test tube contained the most test substance?
D. Other than the control, which test tube contained the least test substance?
E. Did the results agree with your initial hypothesis in every case? Explain why or not.
F. If the color change is not as you expected it to be, what might be the reason(s)?
Discussion
A. What is the purpose of this exercise?
B. Explain the molecular basis as to why Sudan III can be used to detect the presence of lipids, but not sugar or proteins. Why can Biuret, Benedict's, and Iodine Reagents detect the presence of proteins, starches, and sugars, but not lipids?
Experiment Basic Chemistry for Investigating Living Systems
8 ©Hands-On Labs, Inc. www.HOLscience.com
C. What other types of foods or substances contain high levels of lipids?
D. What other types of analytical procedures detect the presence of lipids?
E. Fill in the summary Table 5 in the Lab Report Assistant section by noting which complexing reagents (dyes) can be used to determine which cellular components. Use + to indicate that the dye will detect the component, and – to indicate that it will not detect the component.
Laboratory Summary
What have you learned from doing this laboratory?
