The purpose of this investigation was to see how the concentration of an enzyme affected the rate at which a substance was broken down. We did this by using a white protein called casein. Casein is found in milk powder, it is a protein and used mainly as a binding agent in foods, because it is mad to proteins and joins to a phosphoric acid it belong to a group called the phophoproteins. In terms of in milk it is said to be healthier if it is eaten when it is not denatured. It would become denatured if the protein loses its structure due to temperature, acidity or concentration. The enzyme used in this investigation was Trypsin, this is an enzyme used to degrade proteins, and it is a proteinase enzyme. Trypsin is one of the three main digestive proteinase, the two others include pepsin and chymotrypsin, the jobs for their types of enzymes is to break down dietary proteins e.g. casein, into peptides and amino acids. Trypsin is produced by the pancreas and has a very similar structure to chymotrypsin; the Trypsin we used was from a beefs pancreas.
Apparatus used in this investigation
1. Acidified protease solution
2. Milk powder
3. Standard glass wear
4. Stop Clock
5. Cuvette
6. Colorimeter
7. Measuring cylinder
Before making my hypotheses I investigated what affects rates of reactions and the enzyme structure. The specific shape of the protein determines the active site for specific reactions, which brings me onto the lock and key theory:
This basically can involve a single molecule or more than one molecule with a complementary shape has a shape that fits into the active site. These molecules which are called substrates form a bond with the amino acids on the active site, to produce an enzyme substrate complex, in this form the substrate molecules react much quicker and easily. The other point to this is each enzyme will only catalyse one specific reaction because only one