Question

Enzymes
In this activity, you will follow Demetri, a fellow biology student, as he tests the effects of the lactase enzyme in different conditions and on different solutions.

Estimated time to complete: 2 hours

To begin the experiment, Demetri gathered these materials:

Materials
6 test tubes
safety goggles
3 400-mL beakers
1 microwaveable container
100-mL graduated cylinder
oven mitts
10-mL graduated cylinder
3 tablespoons sugar
a stirrer
75 mL milk
glucose test strips
250 mL water
2 lactase pills
masking tape
a pen
test tube rack

Demetri will use the materials to create the following six solutions:

milk (lactose) in water
milk (lactose) and lactase enzyme in water
milk (lactose) and lactase enzyme in water, heated to boiling
sugar (sucrose) in water
sugar (sucrose) and lactase enzyme in water
sugar (sucrose) and lactase enzyme in water, heated to boiling
Each solution will be made in a test tube. Demetri will insert a glucose test strip into each solution to test for the presence of glucose. The test strip will change color if glucose is present in the solution, as indicated by the following scale.

A glucose test strip bottle and the test strips will change color if glucose is present in the solution as mentioned.

Part A: Hypothesis and Data Collection
Question 1
Look at these molecular structures.

The five molecular structures.

Use the molecular structures to predict which of the six solutions will test positive for glucose. Write your prediction in the answer space. Provide the reasoning behind your prediction.

Answer 1

thoughts on this one?

recall that
- lactose is made up of glucose and galactose
- sucrose is made up of glucose and fructose
- lactase is an enzyme that breaks lactose down into its two component sugars

with that in mind, which of the six solutions do you think will test positive for glucose?