Biology 1 Lab

Chemical Basis of Life – Part I - Carbohydrates

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LAB REPORT

PHOTOS – Include two digital photos with your lab report, either as separate attachments to an e-mail or paste into your document.

1. Photo #1 – Take a photo of your finished experiment in exercise 2, testing for sugars.

(The four test tubes after heating, but while still in the pan.)

Be sure to take a view that shows the colors in all the tubes

2. Photo #2 – Take a photo of the tubes after you have added the iodine solution.

(Again, be sure that you are close enough to see the results clearly.)

3. Photo #3 – Take a photo of the tubes after testing your cereal – Benedict’s and IKI tests.

Exercise 2: Simple Sugars

Observations:

Data Table 2: Benedict’s reagent test for sugar
Test Tubes	A	B	X
Initial Color
Color After 5 Minutes

Questions:

A. What was the initial color of the Benedict’s reagent? How did this compare to the color after heating?

B. Is glucose present in the unknown solution? Explain your answer.

C. What are some medical conditions in which it is necessary to monitor glucose levels?

D. Could the procedure you conducted in this exercise be classified as a quantitative test?

Exercise 3: Complex Carbohydrates

Observations:

Data Table 3: Color change in test tubes with IKI solution
iKi test for starch	A	B	X
Initial Color
Final Color

Questions:

A. Is there starch in the unknown solution? Explain your answer.

B. Why may it be important to test for starch?

C. What types of food may be composed of starch?

Exercise 5: Testing Breakfast Cereal

Observations:

Data Table 5: Cereal testing results
Material tested	biuret reagent	Benedict’s reagent	iKi
Cereal	OMIT
dH2o	OMIT

Questions:

Name of cereral tested:

A. Which macromolecules were present in the cereal?

B. Compare your findings to the nutritional information found on the product label. Do the

results agree with the labeling? If not, what could be a source of error?