Name: _______________________
Glucose Lab
Intro:
Darnell works at the local Kroger on the weekends and likes to watch gaming videos on
his phone during lunch. Darnell got called into the office during lunch and left his phone on the
table while he talked to the manager. When he got back, his phone was gone and the only
thing left was some food scraps on the table. He talked to another coworker who saw what
everyone ate but couldn’t remember who sat at your table or many details. Darnell
remembered that he could use the information he learned in biology to figure out who sat at his
table and who took his phone.
Suspects:
The coworker wrote down what everyone had for lunch and handed it to Darnell.
Below is what he reported:
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Alex ate a BLT sandwich
Nikki had something with mustard. It was weird.
Asia had a peanut butter sandwich. Just peanut butter.
Shawn had a biscuit with jelly on it.
Review of Lipid Lab:
In the previous lab, you tested for the presence of lipids. After testing we found that the
unknown substance on the table was negative for lipids. Mustard and jelly also did not test
positive for lipids and matched the unknown sample. This only helped to narrow down our
suspects to two people. Use the suspect list to determine who is left as a suspect.
Pre-lab:
In this lab you will be testing for the presence of a sugar called glucose.
Glucose is a 6-carbon sugar that is created by plants through photosynthesis
and is found in the blood of animals. When someone who is diabetic tests their
blood sugar levels, they are testing for how much glucose is in their blood.
Glucose, like many sugars gives food a sweet taste and can be found in things
like candy, jelly, and other sweet foods.
This test uses a glucose indicator strip. When there is no glucose, the test strip will stay a blue
color. No change in color is a negative result and means there is no glucose in the sample. If the test
strip changes color to a dark brown or reddish color then it is a positive test. This color change means
there is glucose present in the sample. Be sure to wait at least 30 seconds before recording your result.
Name: _______________________
Pre-Lab Questions:
1. In our lipid lab, we found our unknown substance to be positive or negative for lipids?
2. Which two foods have we narrowed our unknow down to?
3. Which two people are our top suspects?
4. Which sugar are we testing in this lab?
5. What process in plants creates glucose?
6. What is our indicator in this lab?
7. What color will the indicator be if the result is positive and negative?
8. What does a positive result mean?
9. Look at the procedure. How long will you dip the test strip in each sample and how long will
you wait before you record your result?
Materials:
● Collect a sample of the following mixed with water:
○ Mustard
Name: _______________________
○ Jelly
○ Unknown
● 3 glucose indicators
Procedure:
1. Complete your pre-lab questions.
2. Collect your 3 samples and 3 indicator strips.
3. If your samples are not mixed with water, add a small amount of sample to several drops of
water and mix together.
4. Dip the indicator strip into each sample for 1 second and remove.
5. Wait 30 seconds while the indicator reacts with the sample. (The color change will be very
slow)
6. Compare your result with the teachers standards for a positive and negative result.
7. Record your result in the data table and repeat for each sample.
8. Throw away all samples and used glucose indicator strips.
9. Complete the post-lab questions and write your own conclusion for the lab.
Data:
Sample
Color of Indicator
Glucose Present?
Mustard
Jelly
Unknown
Post-lab:
1. What was the purpose of this lab? (What did we want to know?)
Does it match the
unknown?
Name: _______________________
2. What are your experimental results? (What tested positive and negative?)
3. What have you determined the unknown sample to be?
4. Who is our prime suspect?
Conclusion:
Write a conclusion for the lipid and glucose lab below. Your conclusion must include a
purpose, evidence and findings. (why we did the experiment, what data we found in the experiment,
and who stole the phone) Be sure to reason why you believe this person stole the phone!
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