Section 1: Introduction
Enzymes are proteins that are used to accelerate bio chemical reactions. Enzymes can only react with what is called a substrate. This is because the enzyme has a specific working property, such as having a distinct shape that only allows a perfect fit of a substrate. This substrate locks itself to the enzyme and produces a product.
Lactase is an enzyme that breaks down lactose, a milk disaccharide of galactose and glucose. Lactase can only be found inside the inner walls of the small intestine. Some people stop making lactase after a certain age, the person then becomes lactose intolerant. Lactose intolerant is when a person is unable to break down the sugar molecules of milk, with symptoms that include bloating, cramps, and diarrhea.
The purpose of the experiment is to test the specificity of the enzyme lactase. To test the specificity we used lactose and sucrose and checked for glucose in the solution. The next procedure in our experiment is to test for pH and environmental factors and their effects on lactase. We then tested lactase with lactose in contrasting environments and temperatures. The prediction made for specificity was that lactase was only specific to lactose. We also concluded that sucrose and lactose as well as sucrose and water solution would be the highest concentration for glucose.
For the second experiment we predicted that pH 7 would be optimal for lactase function. For the third experiment we predicted that 25°C with milk and lactase would contain the highest glucose concentration, this is because they are close to the natural environment of the lactase in which enzymes function.
Section 2: Materials and Methods
A. Lactase Enzyme Specificity:
The materials used for this lab includes: 4 tests tubes, a micropipette, 2 ml of milk, 1 ml of lactase, 1 ml of water, and a stop watch.
For this lab we wanted to test the specificity of the enzyme lactase, to do this we needed four different test tubes. We labeled the test tubes as follow: Milk + Lactase, Milk + water, Sucrose + Lactase, and Sucrose + water. To only two test tubes we added 2 ml of milk and to the other two test tubes we added 2 ml of sucrose. We inserted these substances into the test tubes by using micropipettes. After adding the substances we quickly added the remaining substance to make the solutions that we labeled on the test tubes. Meaning that to one of the test tubes containing 2 ml of milk we added 1 ml of lactase and to the other test tubes containing 2ml of milk we added 1 ml of water. To the other tests tubes that contained the 2 ml of sucrose we added 1 ml of lactase to one of the test tubes that contained 2 ml of sucrose and to the other test tubes of 2 ml of sucrose we added 1 ml of water. We later let the solution set for two minutes and then tested for glucose. We tested for glucose by using glucose strips and then removing them. After doing so we read the test strips and recorded our observations.
B. Effects of...