1. Calculate the Rf of alanine from the following chromatogram. (5 points)
 

2. A 0.309 g sample of protein was hydrolyzed and NH₃ distilled into 50.00 mL of 0.0189 N HCl. The resulting solution required 23.85 mL of 0.0152 N NaOH to reach neutrality. Calculate the weight of protein in the sample, assuming 16 percent nitrogen in all proteins. Show your work and reasoning (include reactions where necessary). (15 points)

3. Calculate the percent yield if 29.52 g of chitin hydrolyzed in HCl results in 15.975 g glucosamine hydrochloride being obtained. (10 points)

4. Plot the following data and determine the number of µmoles glucose in the tube being assayed in duplicate. (10 points)

                                Contents                           %T             A_{490 nm}
        Tube             2.0 mM Glc       water         (read)         (converted)
          1                    0.0 mL           1.0 mL         100.0             0
          2                    0.2 mL           0.8 mL           57.8             0.238
          3                    0.4 mL           0.6 mL           51.6             0.287
          4                    0.6 mL           0.4 mL           41.2             0.385
          5                    0.8 mL           0.2 mL           32.1             0.493
          6                    1.0 mL           0.0 mL           16.5             0.783
          7                 1.0 mL sample   0.0 mL           87.7             0.570
          8                 1.0 mL sample   0.0 mL           84.0             0.757
 
5. For each of the following reagents or procedures, provide a brief statement of their purpose in the experiments we performed. (10 points)
    a. Diluting enzyme in 0.1% gelatin for kinetic studies.

    b. 1.5 x 10^-4 M p-hydroxymercuribenzoate

    c. diluting stock enzyme in water to determine protein.

    d. Dinitrosalicylate