Question

Learning Task 12-01

The Enzyme Lactase Experiment Design

Which question will your experiment investigate? (select one and delete the others)

How does temperature affect how lactase drops work to break down lactose into glucose and galactose?

How does pH affect how lactase drops work to break down lactose into glucose and galactose?

How does agitation (movement) affect how lactase drops work to break down lactose into glucose and galactose?

What variable will you change in this experiment? This is also called the Independent variable.

How will you change it?

What variable will you measure in this experiment to determine the effect of the variable you changed? This is also called the Dependent variable.

How will you measure it?

What variables will you keep the same in this experiment?

Check off the items in this list that you would use for this experiment. You may add any items you feel you would need.

Skim milk (which contains lactose)	Lactase drops
Graduated cylinder	Eye dropper
Ice cubes	pH paper
Hot plate	Mixing spoon
Thermometer	Vinegar (acidic)
Test tubes Glucose test strips	Baking soda (basic)
Other items you feel you would need to use for this experiment.

Describe what you would do in your experiment. For each step, explain why the step is important. Add more steps if required.

Step:	Why this step is important:

If you actually conducted this experiment, what safety issues would you need to identify?

If you actually conducted this experiment, what appropriate precautions would you take to ensure that you performed the experiment safely?

If you actually conducted this experiment, what results would you expect to see?

Why would you expect these results?

Answer 1

1. The optimum temperature for the enzyme is around 60 degree celcius and in temperatures above and below this the action of the enzyme is reduced.

2. Lactase enzyme requires acidic environment for its action that is in between 2 to 7. If the ph is made to be alkaline the action of enzyme is decreased thatis at ph above 7.

3. Agitation could increase the action of enzyme. During agitation more and more lactose molecules will come in contact with lactase enzyme and will be converted to the disaccharides glucose and galactose.

4. The temperature will be varied in the experiment.

5. The concentration of glucose produced will be measured. Glucose concentration can be determined either by spectrophotometric method or potassium permanganate color change method. In spectrophotometric method the absorbance will be measured and using standard known concentrations of glucose the concentration will be determined. In potassium permanganate method colorless manganese will be produced and the time required for production of colorless solution is dependent on glucose concentration and from the standard known concentrations of glucose the unknown glucose concentration can be determined.

I am supposed to answer only the first four parts. I have answered 5 questions. Please post rest of the questions as another question.