Simple Enzyme Experiments

Most simple enzyme experiments involve food. An enzyme is a biological catalyst or a biological chemical that speeds up a reaction. Enzymes aid an organism to digest food. Use the Scientific Method to make observations, predictions, and hypotheses for the five enzyme experiments.

Experiment one involves gelatin and fresh or frozen pineapple, papaya or kiwi fruit. Will jello set if you add fresh pineapple, papaya or kiwi before cooling? The protease enzyme in pineapple is called bromelain. Schillings Meat Tenderizer contains bromelain. The enzyme in papaya is papain. Accent Meat Tenderizer contains papain. Will jello set if you add Meat Tenderizer? Will jello set if you add canned pineapple or cooked pineapple? What happens to gelatin if you add fresh pineapple after it has set? What happens to the enzyme if it is cooked?

Experiment two involves raw potato and hydrogen peroxide you can find in the grocery store or neighborhood Walgreens. Peroxidase is the enzyme in potato. Peroxidase breaks hydrogen peroxide down into water and oxygen. Place a drop of hydrogen peroxide onto a slice or cube of raw potato and observe what happens. Next you will test the rate of reaction between the hydrogen peroxide and potato at various temperatures to determine at what temperature an enzyme works the fastest and at what temperature an enzyme is destroyed or denatured. You will cool or heat potato pieces to add to hydrogen peroxide. You will observe if the reaction is faster, slower, or stops completely.

Experiment three: Repeat experiment two with yeast, raw turnip, horseradish, or raw beef liver.  Catalase is the enzyme in these materials.

Experiment four will determine if the concentration of the enzyme changes the rate of reaction. You will soak circles of filter paper created with a paper punch in the mixture of enzyme made from a package of yeast.  Then you will place the enzyme soaked circle into 10 ml of hydrogen peroxide. You will count the number of seconds it takes a circle to rise to the top of liquid in a test tube to determine the reaction rate. The oxygen released will collect on the paper circle making it rise to the surface. When the oxygen gas is released, the paper circle will return to the bottom of the test tube to collect more oxygen bubbles. Yeast is the easiest organism to use for this experiment because you can dilute the yeast solution to make several concentrations of peroxidase.

Experiment five is a simulated enzyme reaction using toothpicks called toothpickase. You will use your thumb and index finger (the enzyme) to break a toothpick in half (use only one hand).  Place 50 toothpicks on a paper plate. You will count how many toothpicks you can break in a minute. Does the reaction rate decrease as more toothpicks are broken? Then you will cool your hand in ice water and count how many toothpicks you can break in a minute. Repeat but scatter the 50 toothpicks over a table surface so that the enzyme has to work harder to find a toothpick. Repeat the experiment using both hands or two people; this will double the amount of enzyme. If you run out of toothpicks before a minute is up, record the time. What do you think would happen to rate of reaction if straight pins were mixed in with the toothpicks?