Pre-Lab Questions
1. What color is a negative test for protein? What color is a positive test for protein?
2. What color is a negative test for sugar? What color is a positive test for sugar?
3. What color indicates an acidic pH? What color indicates a basic pH?
Part A Testing for Proteins
Post-Lab Questions
1. Did you predict correctly? Why or why not? Be specific!
2. Identify the positive and negative controls used in this experiment. Why are they used, and why they are necessary?
3. The major classes of organic molecules are proteins, lipids, carbohydrates and nucleic acids. Identify the major class(es) of organic molecule that is/are found in the following food items:
• Coca-cola
• Ground beef
• Brussel sprouts
• Gummi bears
• String cheese
• Ice cream
• Peanuts
• Olive oil
Part B Testing for Reducing Sugars
Post-Lab Questions
1. What results would you expect if you tested the following substances with both Benedict's solution and Biuret solution?
• Honey
• Lettuce
• Butter
• Tofu
Part C What Household Substances are Acidic or Basic?
Post-Lab Questions
1. What is the purpose of determining the pH of the acetic acid and the sodium bicarbonate solution before testing the other household substances?
2. Name two acids and two bases commonly found in a grocery store.
3. What is similar about the acids you identified? What is similar about the bases you identified? What can you conclude about acids and bases based on these similarities?