Title: Lactose Lab

Introduction: Background :Enzymes are important components of digestion because they break down large food molecules into smaller chemical subunits. One digestive enzyme, lactase, lactose (a disaccharide found in milk) into the monosaccharides glucose and galactose.

Disaccharide: Carbohydrate made Up of two sugars bonded together Lactose Glucose Galactose Disaccharide: Carbohydrate made Up of two sugars bonded together Sucrose Glucose Fructose Substrates bind to an enzyme at certain places called active sites. The enzyme brings substrates together and weakens their bonds. The catalyzed reaction forms a product that is released from the enzyme.

Purpose Hypothesis What question will you explore? What do you want to study? Hypothesis What do you think will happen? Answer your question

Purpose: How will the lactase enzyme pill affect the sugars in the milk versus the sugar water? Hypothesis: I think the lactase pill will………in the milk. I think the lactase pill will………in the sugar water.

Materials: (per group) Two beakers 10 mL of milk 10 mL of sucrose water 2 Lactase enzyme pill 4 Glucose test strips 1 Glucose reading chart

Procedures Pour 10 mL of milk into 1 beakers. Test Milk for presence of glucose by dipping the glucose strip into the milk and reading the color. Test sugar water for presence of glucose by dipping the glucose strip into the milk and reading the color. Add commercial form of lactase by breaking up a lactase pill into the 10mL of milk and test it again for glucose. 5. Add commercial form of lactase by breaking up a lactase pill into the 10mL of sugar water and test it again for glucose.

Data collection Solution Reading of stick Before enzyme Reading of Stick after enzyme Milk Sucrose water mg/dl 1000 2000 100 250 500

Data Analysis 1. Explain your data Table: 2. What was the control in this experiment? 3. What was the independent variable? 4. What was the dependent variable? 5. What were the constants?

Error Analysis Explain any mistakes or circumstances that could have skewed the results: 1. What sources of error may have existed? 2. How might the experiment be conducted differently? 3. What additional questions arose from the experiment?

Conclusion 1. Was your hypothesis accepted or rejected? 2. How do these results relate to enzymes (proteins) and carbohydrates? 3. Why did the lactase pill take apart lactose into glucose and galactose and not take apart the sucrose into glucose and fructose? 4. What do you think makes people lactose intolerant?

Sucrose Lactose

References