(B) Follow the directions for testing various organic nutrients as described on your Procedure page. Record your results by answering the questions below.
- What color appears in each test tube before it is heated? ________________________
- After heating, what color changes occured in the test tube 1 ? __________________________________________________________________________________
- What color finally appears in tube 1? ____________________________________________________
- What was the purpose of tube 1, which was a negative test ( no color change) __________________________________________________________________________________
- Describe a positive test for sugar. __________________________________________________________________________________
- What color change occurred in test tube 1? ________________________________________________
- What color change occurred in test tube 2? ________________________________________________
- Describe a positive test for starch. __________________________________________________________________________________
- What do you observe on the brown paper (with corn oil drops) as you hold it to the light? __________________________________________________________________________________
- After allowing the water on the paper to dry, compare the water spot with the oil spot. __________________________________________________________________________________
Summary
- What is the one element common to all organic compounds? _____________________
- Why is the element you’ve just identified in question one so unique? ____________________________________________________________________________________________________________________________________________________________________
- Name the three elements in carbohydrates. ________________________________________________
- What is lost when sugar molecules join together to form double sugar ( disaccarides) or starch molecules? _________________________________________________________________________
- The word carbohydrates is made up of carbon and hydrates (water). Why is the word carbohydrates a good description? ___________________________________________________________________
- What are the three elements in sugar? ___________________________________________________
- How can you prove the presence of carbon in sugar? __________________________________________________________________________________
Complete the following Table with your testing chemicals and results.