Biology 102/103 Lab 2: the Chemistry of Life

Pre-Lab Questions

1. Nitrogen fixation is a natural process by which inert or unreactive forms of nitrogen are transformed into usable nitrogen. Why is this process important to life?

2. Given when you have learned about the hydrogen bonding shared between nucleic acids in DNA, which pair is more stable under increasing heat: adenine and thymine, or cytosine and guanine? Explain why.

3. Which of the following is not an organic molecule; Methane (CH4), Fructose (C6H12O6), Ethanol (C6H12O), or Ammonia (NH3)? How do you know?

Experiment 1: Testing for Proteins

Data Tables and Post-Lab Assessment

Table 1: A Priori Predictions

Table 1: A Priori Predictions

Sample Will There be Protein Present? Initial Color Final Color

1 - Albumin Solution

2 - Gelatin Solution

3 - Glucose

4 - Water

5 - Unknown

Table 2: Testing for Proteins Results

Table 2: Testing for Proteins Results

Sample Initial Color Initial Color Is Protein Present?

1 - Albumin Solution

2 - Gelatin Solution

3 - Glucose

4 - Water

5 - Unknown

Post-Lab Questions

1. How did your a priori predictions from Table 1 compare to your actual results in Table 2? If there were any inconsistencies, explain why this occurred.

2. Identify the positive and negative controls used in this experiment. Explain how each of these controls are used, and why they are necessary to validate the experimental results.

3. Identify two regions which proteins are vital components in the human body. Why are they important to these regions?

4. Diet and nutrition are closely linked to the study of biomolecules. Describe one method by which you could monitor your food intake to ensure the cells in your body have the materials necessary to function.

Experiment 2: Testing for Reducing Sugars

Data Tables and Post-Lab Assessment

Table 3: Testing for Reducing Sugars Results

Table 3: Testing for Reducing Sugars Results...