BIOL 1107 In each of the two tests (starch and sugar)
Question # 00346169
Posted By:
Updated on: 07/26/2016 07:15 AM Due on: 07/26/2016
Biological Macromolecules
Hands-On Labs, Inc.
Version 42-0291-00-02
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.
Exercise 1: Starch and Sugar
Data Table 1. Benedict’s Reagent Data.
Sample
Initial Color
Final Color
Reducing Sugar Present
in Sample? Y or N
Final Color
Starch Present in Sample?
Y or N
dH2O
Albumin
Unknown
Milk
Glucose
Data Table 2. Lugol’s Iodine Data.
Sample
Initial Color
dH2O
Albumin
1
Unknown
Milk
Starch
Raw Potato
Questions
A. In each of the two tests (starch and sugar) a positive and negative control was used. What
was the positive control in each of the tests and what was the negative control. Explain
your answers.
B. Did the Benedict’s test for reducing sugars net a positive or negative result for milk?
Research the sugar content of milk and the definition of a reducing sugar to explain if your
result is what you would expect.
C. Based on your results, is sugar and/or starch present in your Unknown? Use your results to
explain your answer.
Exercise 2: Proteins and Lipids
Data Table 3. Biuret’s Reagent Data.
Sample
Initial Color
Intermediate Color
Final Color
Protein Present
in Sample? Y or
N
dH2O
Clear
Light blue
Light blue
No
Albumin
Mainly cloudly;
a little clear
Light Purple
Light purple
Yes
2
Unknow
n
Slightly cloudy; a
little clear
Purple
Purple
Yes
Milk
A clear white
Purple
Purple
Yes
Data Table 4. Lipid Observations.
Sample
Sample Observations
Lipid Present in
Sample? Y or N
Distilled water
Red on the pencil
No
Albumin
Red on a pencil
No
Unknown
Not a lot of red on the pencil
Not much
Milk
Not a lot of red on the pencil
Not much
Vegetable oil
Red on a pencil
Yes
Questions
A. Review the Data Tables in Exercises 1 and 2. Compare the results of the Unknown for all
tests to the results for the various known samples to determine the identity of the
Unknown. Explain the identity of the Unknown using your experiment results in the
exercises to help explain and support your answer.
B. Eggs are known to contain cholesterol which is a lipid. Did your experiment results indicate
a presence of lipids in the albumin solution? Think about this result and where cholesterol
is present in eggs to explain how your results support or reject cholesterol in eggs. How
could you test this? Explain the experiment that you would perform to test this.
Hands-On Labs, Inc.
Version 42-0291-00-02
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.
Exercise 1: Starch and Sugar
Data Table 1. Benedict’s Reagent Data.
Sample
Initial Color
Final Color
Reducing Sugar Present
in Sample? Y or N
Final Color
Starch Present in Sample?
Y or N
dH2O
Albumin
Unknown
Milk
Glucose
Data Table 2. Lugol’s Iodine Data.
Sample
Initial Color
dH2O
Albumin
1
Unknown
Milk
Starch
Raw Potato
Questions
A. In each of the two tests (starch and sugar) a positive and negative control was used. What
was the positive control in each of the tests and what was the negative control. Explain
your answers.
B. Did the Benedict’s test for reducing sugars net a positive or negative result for milk?
Research the sugar content of milk and the definition of a reducing sugar to explain if your
result is what you would expect.
C. Based on your results, is sugar and/or starch present in your Unknown? Use your results to
explain your answer.
Exercise 2: Proteins and Lipids
Data Table 3. Biuret’s Reagent Data.
Sample
Initial Color
Intermediate Color
Final Color
Protein Present
in Sample? Y or
N
dH2O
Clear
Light blue
Light blue
No
Albumin
Mainly cloudly;
a little clear
Light Purple
Light purple
Yes
2
Unknow
n
Slightly cloudy; a
little clear
Purple
Purple
Yes
Milk
A clear white
Purple
Purple
Yes
Data Table 4. Lipid Observations.
Sample
Sample Observations
Lipid Present in
Sample? Y or N
Distilled water
Red on the pencil
No
Albumin
Red on a pencil
No
Unknown
Not a lot of red on the pencil
Not much
Milk
Not a lot of red on the pencil
Not much
Vegetable oil
Red on a pencil
Yes
Questions
A. Review the Data Tables in Exercises 1 and 2. Compare the results of the Unknown for all
tests to the results for the various known samples to determine the identity of the
Unknown. Explain the identity of the Unknown using your experiment results in the
exercises to help explain and support your answer.
B. Eggs are known to contain cholesterol which is a lipid. Did your experiment results indicate
a presence of lipids in the albumin solution? Think about this result and where cholesterol
is present in eggs to explain how your results support or reject cholesterol in eggs. How
could you test this? Explain the experiment that you would perform to test this.
-
Rating:
/5
Solution: BIOL 1107 In each of the two tests (starch and sugar)