Post-Lab Questions 1. \"Little Miss Muffet sat on a tuffet, eating her curds and
ID: 304001 • Letter: P
Question
Post-Lab Questions 1. "Little Miss Muffet sat on a tuffet, eating her curds and whey." What was she eating and where d 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 mil, 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 (ie, adds a -NO; group)? CH-COOH NH2 6. Does albumin and casein contain tyrosine? How do you know?Explanation / Answer
1. Curds and whey are the lumps (solid masses) and liquid part of cottage cheese.
Cottage cheese is made from skimmed milk. All the protein that present in the milk is separated by adding a enzyme 'rennin' (chymosin). The enzyme found in stomach of cud- chewing animal like calf.
'Rennin' is used to assemble (coagulate) some of the proteins in milk. Such type of coagulated protein is known as curd and the unassembled protein is called whey.