Question

Table 2. Reaction for proteins test tube Solution 2ml egg white Biuret Reaction Final color and conclusions Solution separated at the top Light green; homogenous 2ml high fructose corn 2ml 1% amino acid solution 2ml distilled water Light blue Light blue 2ml 1% protein solution Purple 2ml 1 starch Light blue 2ml 1% glucose solution Light blue 2ml Muscle Milk Light purple 2ml 1% protein shake Half purple, separated 2ml 1% BCAA shake Which one of the solutions is the positive control, and what color was it? Which one of the solutions is the negative control for the Bluret reaction, and what color was it? Question 1 Question which contains more peptide bonds, egg albumin or protein shake? How do you know? Question D o free amino acids have peptide bonds? What solution of your experiment supports your answer?

Answer 1

Answers:

1. Positive control : 2ml 1% of protein solution colour with Biuret reagent is purple.

Negative control : 2 ml distilled water colour with Biuret reagent is Light blue.

2. Protein Shake contains more peptide bonds. The greater the number of peptide bonds in a solution the greater the intensity of purple colour. Here the protein shake is half purple.

3. Free amino acids do not have a peptide bond. Biuret reagent works only with peptide bonds, here it is shown that free amino acid solution with Biuret reagent gives a light blue colour which indicates a negative for peptide bond.

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