Post-Lab Questions 1. "Little Miss Muffet sat on a tuffet, eating her curds and whey." What was she eating and where did it come from? 2. In order for the ninhydrin test to work, what functional group must be present? 3. According to the equation for the ninhydrin reaction with an amino acid (see Background section), an aldehyde and CO are products. What parts of the amino acid give rise to these products? 4. Using the percentage you obtained for casein in milk, how many grams of casein are in a glass of milk (175 g)? 5. Below is the structure of phenylalanine. Why should this amino acid give a yellow color with concentrated nitric acid? What part of the molecule becomes nitrated (i.e., adds a -NO group)? CH-COOH I NH 6. Does albumin and casein contain tyrosine? How do you know? 187