COOL Classroom 2.1

Discover Enzymes - The Stuff of Life

Go-go Speed Racer

Millions and millions of chemical reactions take place in our bodies every second. Without these reactions we wouldn’t be able to move, breathe, digest our food, grow or do anything!

Every reaction that takes place involves the breaking down or building up of chemical bonds and just like everything else in the world this requires energy. The energy required to break existing chemical bonds and create new ones is called activation energy. Without activation energy, reactions can’t get started.

Many of the chemical reactions that are essential to the healthy functioning of our bodies have high activation energies and proceed very slowly under normal conditions. The molecules involved in these reactions may be abundant, and in close proximity to each other, but the arrangement of their chemical bonds prevent them from coming together to react. So how do our bodies, and other living organisms, speed up these critical reactions needed to survive? They use catalysts!

Catalysts are substances that cause or accelerate chemical reactions without themselves being altered.

For example, molecules that only react a few hundred times an hour under normal conditions may react hundreds of thousands of times a second with the help of a catalyst.

Enter the Enzyme!

Enzymes are organic molecules (either proteins or nucleic acids) that serve as catalysts in the cells of ALL living organisms. Enzymes have unique structures which enable them to bring together two molecules causing their reaction to occur much faster.

Enzymes assist reactions, but they are not changed in the process. Because of this, enzymes can be used over and over and over again within a cell, participating in millions of reactions. However, just like a tire on a car that rolls and rolls and rolls but ultimately wears out, eventually the enzyme breaks down and a new one will take its place.

Here is a list of some enzymes and what they do:

Enzyme Name Function
Lysozome Breaks down the cell wall of many types of bacteria
Pepsin Breaks proteins into simpler molecules
Chymotrypsin Breaks proteins into simpler molecules
Synthase Forms two sugar molecules into a starch molecule
Amylase Breaks starch molecules apart into their component sugar molecules
Sucrase Breaks apart sucrose molecules into its components, glucose and fructose

DO Try this at Home! – Put an Enzyme to Work!


The Cells in our body use the information in our genes to make proteins. Proteins are used for many functions, including transporting materials, communicating with other cells, and facilitating chemical reactions. Enzymes are a type of protein that makes possible various chemical reactions that cells need. This is a simple experiment to show how enzymes work.
Materials needed:

  • One fresh, ripe pineapple
  • Any type of gelatin product (flavored or not)

To do ahead of time:

  1. Prepare the gelatin product according to the package directions. To make only one serving of Jell-O, dissolve 1 3/4 tablespoons Jell-O gelatin in 1/2 cup boiling water, then stir in 1/2 cup of cold water. Each small box of Jell-O is the equivalent of one packet of unflavored gelatin.
  2. Cool in refrigerator until the Jell-O sets.

To begin the experiment:

  1. Cut a piece of the ripe pineapple and place it on the gelatin.
  2. Observe and record the results.
  3. What happened? Can you figure out why? Enzymes played a role!

Lesson Credit: The University of Utah, Genetic Science Learning Center

Test your knowledge!

Take this quiz on enzymes.