Principle(s) Illustrated

1. Enzymes are proteins that catalyze chemical reactions.

2. Catalysts speed up chemical reactions and lower the activation energy needed.

Standards

• Biology 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.

Questioning Script

Prior knowledge & experience:

Students know the four organic, macromolecules (carbohydrates, nucleic acids, lipids and proteins) are polymers composed of monomer subunits.

Root question:

Students make observations of two containers of Jello that were made at the same time, under the same conditions and with the same ingredients except, one was made with fresh pineapple.

Question: Why did the Jello with the pineapple not set up? Prompt students to make careful observations and develop a hypothesis for why the pineapple jello is still liquid.

Target response

There is an enzyme in the pineapple (bromelain) that breaks down protein substrates.

Common Misconceptions:

The pineapple jello wasn't refrigerated as long.

The pineapple has something in it (acid) that dissolves the jello.

After the students form their hypotheses, in groups they will watch a video of how the teacher made the Jello.

Real world relevance discussion:

What would happen if you order a protein shake from a juice bar and add fresh pineapple?