Purpose of this lab: to demonstrate the function of enzymes.
Safety Precautions: There is a hot plate. Do not touch it! Unless, of course, it isn't plugged in. Also, wear goggles always (and put them away in their respective cubby at 3:15).
Introduction: Lactose is a molecule found in dairy products. In this lab, we used skim milk as our dairy representative. Lactase is the enzyme, which metabolizes lactose, breaking it down into its components, galactose and glucose. Those who need to ingest Lactase cannot digest lactose, and are thereby diagnosed as lactose intolerant.
Procedure: we tested five different types of solution: Milk and our enzyme solution (i.e. Lactase dissolved into water), milk and water, sucrose solution and enzyme solution, the denatured enzyme solution and milk, and sucrose solution and distilled water. We tested for the presence of glucose in each of these solutions. In the solutions consisting of the enzyme solution and a component, we were testing to see if the enzyme broke down the sucrose or lactose into its component, glucose.
Observations: Glucose was only present in the milk and enzyme solution. We predicted this outcome.
Analysis: This is a diagram of the of the successful effects of the lactase when it reacts with lactose.
Why did lactase react to lactose but not to sucrose?
The lactase only reacted with the lactose because enzymes by definition are very specific to their reactant molecules, or substrates. If we were working with a catalyst, perhaps the sucrose would've reacted as well, because chemical catalysts typically react with a broad spectrum of reactants.
What happened when the lactase was boiled?
Bubbles formed when the lactase was boiled.
Would lowering the pH of the enzyme solution affect the enzyme?
Lowering the pH of the enzyme solution wouldn't affect the enzyme because the stomach where lactase reacts is very acidic, so the enzyme isn't denatured in those conditions.
Lactase is speeding up what type of chemical reaction - dehydration or hydrolysis?
Hydrolysis is the breaking down of compounds with water. We had to dissolve the lactase in order for it to work. Thus, the chemical reaction constitutes hydrolysis.