1. Albumin Solution

2. Gelatin Solution

3. Glucose

4. Water

5. Unknown

Post-Lab Questions

1. Record your hypothesis about what will happen when Biuret solution is mixed with the solutions from test tubes 1, 2, 3, and 4 here. Be sure to use scientific reasoning to support your hypothesis.

the correct answer is B

The Biuret test is used to check the presence of protein in a solution. The Biuret solution is a blue colored solution containing copper (II) ions. The copper ions react with the peptide bonds of proteins and this reaction results in change in color from a blue to pink-purple solution.

1. Color will change to pink-purple due to reaction of Biuret copper (ions) ions with the peptide bonds of Albumin.

2. Color change to pink-purple due to reaction of Biuret copper (ions) ions with the peptide bonds of gelatin.

3. Color remains blue since there are no peptide bonds.

4. Color will not change to pink-purple color.

5. If the unknown is a protein then the color will change to pink-purple.