Proving enzymes work (Elba Lopez)

Principle(s) Illustrated: Proteins catalyze biochemical reactions

Standards

7th Grade

  • 7.5.b.Students know organ systems function because of the contributions of individual organs, tissues, and cells. The failure of any part can affect the entire system.

  • 7.7.c. Communicate the logical connection among hypotheses, science concepts, tests conducted, data collected, and conclusions drawn from the scientific evidence.

  • 7.7.e. Communicate the steps and results from an investigation in written reports and oral presentations

8th Grade

  • 8.5.a.Students know reactant atoms and molecules interact to form products with different chemical properties.

  • 8.6.c.Students know that living organisms have many different kinds of molecules, including small ones, such as water and salt, and very large ones, such as carbo­hydrates, fats, proteins, and DNA.

Bio:

  • 1.b.Students know enzymes are proteins that catalyze biochemical reactions without altering the reaction equilibrium and the activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings.

Materials

  • liver

  • test tubes with cap

  • peroxide

  • wooden splint

  • matches/lighter

Procedure

The liver must be placed on ice or refrigerated so that the enzymes do not denature.

1. place a piece of liver into a test tube

2. add about 5 drops of peroxide

3. place the cap on the tube

4. light a wooden splint and put it out so that it still glows red

5. open the test tube and slowly place it inside (do not submerge into the liver/peroxide mixture)

Data:

Enzymes

For comparison:

repeat the same procedure using water to show that liver and the water do not have the same reaction as liver and peroxide.

Prior knowledge & experience:

Enzyme-substrate complex

functions of the liver

Root question:

Target response:

The liver contains an enzyme that breaks down the peroxide build-up in our bodies into safe molecules, oxygen and water.

Common Misconceptions:

Peroxide is flammable and that's why the wooden splint relights

Photographs and Movies

http://bit.ly/qJ1c51

Sources:

http://en.wikipedia.org/wiki/Catalase

http://www.sciencegeek.net/Biology/biopdfs/Lab_Catalase.pdf

http://www.biologycorner.com/worksheets/enzyme_lab.html#.Uj8JST9jPSo