I had a lab last week of the hydrolysis of a protein by using the substrate of the enzyme of Trypsin. My teacher wants to know the purpose of the experiment.

I don't quite get what you're trying to ask but I can tell you that trypsin is an enzyme which is used to break down most arbitrary proteins into polypeptides. Polypeptides consist of 50 or less amino acids in a continuous chain (without any breaks). Proteins are longer and always have a complex 3D structure. The purpose of the enzyme trypsin (also found in the human stomach) is to break the protein down into polypeptides before they are broken down into amino acids (which are more soluble and can pass through biological surfaces) in the small intestine.

OK, based on what you wrote, it seems like you're trying to prove that the function of trypsin is to reduce proteins. There's a specific test using a blue-colored mixture of copper (II) sulphate and sodium hydroxide which is used to test the presence of peptide bonds. If proteins are present in a solution, the copper ion complexes to the peptide bond (in proteins) and the color of the solution changes from blue to mauve. In the case of short polypeptides, the copper- ligand complex absorbs at different frequencies and gives a pinkish color.

Let's say that you have a food sample and you immerse it in the blue solution. If there are any proteins present in solution, then the solution should change color. (blue to mauve) When it turns mauve, you can then add trypsin to the sample. What you would observe is that the color changes again and this would confirm the question of the purpose of the enzyme. (which is to reduce proteins)