Lactase and Glucose Lab

Purpose: To explore the purpose of the lactase enzyme and how it affects lactose levels to increase glucose. This experiment explores the unique effects the lactase enzyme has on milk, specifically, how effectively, and how much enzyme is required to properly break down the lactose in the milk, leaving higher glucose levels.  This purpose of this experiment is to find out how the level of lactase enzyme can affect the rate of the reaction to leave more glucose. Our hypothesis is that the more lactase enzyme is used, the more the lactase and lactose will react, leaving higher glucose levels, than with a lower volume of lactase enzyme.


  • Lactase
  • 75 mL of 2% milk
  • 6 test tubes
  • Stirring rod
  • 12 glucose test strips
  • Test tube rack
  • 25ml graduated cylinder
  • 80mL glass beaker
  • Stoppers
  • Timer

Lab procedure


  1. Number test tubes from 1-6
  2. Measure out and add 15mL of skim milk to each test tube.
  3. Test glucose levels in each test tube, record in data table
  4. Keep test tube 1 as a control group, do not alter anything in test tube 1
  5. Wait 2 minutes and measure the glucose levels of test tube 1
  6. Record results in the Data table below
  7. Add 2 drop of lactase to test tube 2
  8. Wait 2 minutes, and measure the glucose levels of test tube 2
  9. Record results in the Data table below
  10. Add 4 drops of lactase to test tube 3
  11. Wait 2 minutes and measure the glucose levels of test tube 3
  12. Record results in the Data table below
  13. Add  6 drops of lactase to test tube 4
  14. Wait 2 minutes and measure the glucose levels of test tube 4
  15. Record results in the Data table below
  16. Add 8 drops of lactase to test tube 5
  17. Wait 2 minutes and measure the glucose levels of test tube 5
  18. Record results in the Data table below
  19. Add 10 drops of lactase to test tube 6
  20. Wait 2 minutes and measure the glucose levels of test tube 6
  21. Record results in the Data table below
  22. Clean and put away all equipment




Data and observations

Test Tube Lactose/skim milk (mL) Glucose level before Drops of Lactose Glucose levels after change of Glucose levels
1 15mL 0.0 0 0.0 0.0
2 15mL 0.0 2 28 28
3 15mL 0.0 4 14 14
4 15mL 0.0 6 28 28
5 15mL 0.0 8 56 56
6 15mL 0.0 10 111 111

Analysis + Conclusion

Things to discuss in your group:

  1. What factors can affect the reaction rate for an enzyme-mediated reaction

The factors are: the PH, the temperature, the enzyme concentration, the substrate concentration, inhibitors and activators.

  1. What do we know about lactase

The lactase will be able to withstand the acid PH of the stomach so that the pill is going to be activated in the small intestine.

  1. What are we curious about / what would be beneficial to test

We would like to know what is the purpose of the lactase in our body and how its enzymes act against lactose intolerance

  1. What scientific method steps will we use
  2. By step: 1) ask a question 2) do background research, 3) construct a hypothesis, 4) test the hypothesis with an experiment 5) if the procedure works, keep going if not restart the experiment, 6) analyze data and do the conclusion, 7) if the results align with the hypothesis then communicate results and if not start again from the hypothesis.
  3. What scientific process skills will we use

We will use: 1) observing, 2) classifying, 3) measuring, 4) communicating, 5) inferring, 6) predicting

  1. What factors can affect our reaction / how do we ensure this is a controlled experiment

The factors that could affect our reaction are: if putting too much lactose maybe the lactase we put inside won’t be enough to “digest” the lactose, we can’t exactly reproduce the conditions of our stomach. The experiment is controlled because we have precise data and we are measuring everything.







agar lab

  1. 1. The cube that proved itself to be the most efficient when it came to diffusion was the 1 cm cube. 




    2. I believe that the smaller size that this cube had, allowed for the diffusion to be more easily and rapidly expand across the cube. Thanks to its volume to surface area ratio. This cube had the highest ratio out of all the others, therefore having a higher diffusion efficiency.

    3. Because the cells would be less efficient in the process of diffusion, which is an important process in cells, as it helps export nutrients, water, and oxygen between living cells. It would take much more time to diffuse if they were larger.

    4. Out of the three cubes (A, B, and C), C (4:1) would be the most efficient in maximizing diffusion as it has the lowest Surface to Volume ratio out of the three cubes. The higher ratio means that this cube has less volume and less surface area, so it would be easier to diffuse.

    5. We have bigger organs that are made up of smaller cells. This allows for covering the maximum amount of surface area so that gases can be exchanged much more efficiently.

    6. Because of the SA: Volume the ratio decreases as the size of an object decreases as demonstrated by the lab data. There is a ratio limit where the size is too large to be able to diffuse efficiently and provide nutrients, water, and oxygen.

    7. The variety of cells is an advantage that multicellular organisms have. This is because each type of cell has its own function to do, each one being more complex compared to unicellular organisms. Being multicellular, different organs to have different functions such as the organs in the circulatory, digestive, reproductive, and respiratory systems.

DNA molecule project

  1. Explain the structure of DNA – use the terms nucleotides, antiparallel, strands, and complementary base pairing.


DNA is made up of sugars, phosphates, and nitrogen. The sugars and phosphates create the two backbones made of sugar-phosphates and nucleotides. The bases of the nucleotides are inside the ladder shape. The two strands of DNA are antiparallel as they are read in opposite directions. Certain bases attract each other and create what is called complementary base pairing. There are four bases Adenine, Thymine, Guanine, and Cytosine. The two pieces of DNA are kept together by hydrogen bonds in the middle of the nucleic acid. DNA is replicated by being split into two by a helicase and then the two strands are paired with different strands through complementary base pairing. This process is called  DNA polymerase. The result is two identical DNA strands. This is the only process for how DNA is able to replicate.

2. This activity really explained DNA replication and how it can twist into a double helix, also it was a lot easier to build in in 3D then to see it on an image. To improve the project I think that we should use mini marshmallows to represent the complementary base pairing and twizzlers or some long piece of candy to form the two backbones. But the watermelon gummy and the two bigfoot gummies did a great job representing DNA polymerase and the unzipping of DNA.


The DNA twisted into a double helix



The unzipping of DNA with the watermelon showing the DNA helicase



The strands are now separated and the big blue foot candy shows the DNA polymerase that find different strands for complementary base pairing



The end product is two identical strands of DNA