Toothpick-ase: An Introduction to Enzyme Kinetics

In this activity you will be modeling enzyme action using toothpicks and your fingers. The toothpicks represent the substrate in this reaction and your thumbs and index fingers represent the enzyme toothpick-ase. The space between your thumb and index finger (where you grip the toothpick), represents the active site of this enzyme.

Pile 41 toothpicks on the desk in front of you. In a period of 10 seconds, break as many toothpicks as you can with the enzyme toothpick-ase (toothpicks must be broken one at a time, by holding the toothpick between you thumb and index fingers and applying pressure). Count and record the number of broken pieces (products). Place all broken and unbroken toothpicks in the same pile and repeat breaking for another 10 second period (toothpicks can only be broken once). Count and record the number of broken pieces during that 10 second time period. Repeat this procedure as many times as is necessary to break all toothpicks.

Make an appropriate graph to illustrate the rate of reaction over time.

Modified from the work of Patricia Glidewell, Marist School, Atlanta, GA.