Lactase enzyme lab OBJECTIVES: 1. Understand how biological molecules are essential to the survival of living organisms * * 2. Compare the structures and functions of the major biological molecules(carbohydrates, proteins, lipids, and nucleic acids) as related to the survival of organisms.
* 3. Investigate and describe the structure and function of enzymes and explain their importance in biological systems.
Purpose:
This lab will examine the specificity of an enzyme (lactase) to a specific substrate (lactose). Students will observe the actions of the enzyme and how shape is important to enzyme reactions.
Background information:
Lactose, the sugar found in milk, is a disaccharide composed of glucose and galactose (both six-sided sugars). Sucrose, ordinary table sugar, is also a disaccharide composed of fructose and glucose. Glucose is a six-sided sugar and fructose is a five-sided sugar.
Lactase is an enzyme that breaks lactose down into galactose and glucose. Lactase can be purchased in pill form by people who are lactose intolerant. These people lack the enzyme, lactase, and cannot break down the sugar lactose into its component parts.
Although lactose is similar to sucrose, lactase will break down only lactose because of the shape of the sugar. In this lab, you will see lactase break lactose down into galactose and glucose. You will also observe what happens if the shape of lactase is changed due to heating.
Materials/ resources:
* Lactase tablets: these can be bought in any drug store or grocery store. * Fifteen milliliters of milk: any milk will work. * Water: used for dissolving the lactase tablet, dissolving the sucrose and boiling the lactase. * Sucrose: five grams per group. *