Download Enzymes Directions Toothpick Biochemistrydirection

Toothpick Biochemistry
Experiments with Enzyme Kinetics
Introduction: Without enzymes, biochemical processes would grind to a halt. The chemical reactions that keep us alive
would be so slow, we could not survive. Since it is difficult to observe processes at the molecular level, we will be using a
model to demonstrate some important relationships governing enzyme activity.
LT: By using a model, I will be able to explain the relationship between enzymes, substrates and reaction rates.
Materials: Shallow dish, timer (w/seconds), paperclips, toothpicks, graph paper or computer to generate graph.
Procedure:
Part A. Rate of Product formation
1. Place 90-100 wooden toothpicks in a shallow bowl. The toothpicks represent the substrate (reactants) in this reaction.
2. Assign roles: In your group, one person will be the timer, one will be the data recorder , the third will be the “enzyme”
and the fourth can graph the data as you go.
3. The enzyme functions by randomly selection toothpicks WITHOUT LOOKING at the bowl and snapping the toothpicks
in half using thumb, index finger and middle finger ONLY. All “products” (broken toothpicks) are placed in the bowl.
4. The experiment is conducted in 20 second intervals. The timer calls out “start” and then audibly marks each 20 second
interval. The recorder tallies the cumulative number of toothpicks broken as each 20 second interval is called out (this is
continuous). A minimum of 14 data points should be collected.
5. Graph the results by plotting product formed (the total number of toothpicks broken) vs. time (20 sec, 40 sec, etc)
The person graphing can do this as you go, on graph paper or on the computer.
Part B. Reaction Rate vs. Substrate concentration
1. Place 80-100 clips in the bowl. The paper clips represent the “solvent” in which the toothpicks are “dissolved”.
Different concentrations are modeled by mixing different numbers of toothpicks in with the paperclips.
2. For the first trial, place 10 toothpicks in the bowl with the paper clips. The enzyme has 20 seconds to “react” (break as
many toothpicks as possible.) Record the number broken at concentration 10.
3. Remove all the broken toothpicks and repeat step 2 with concentrations of 20, 30, 40, up to at least 100 toothpicks
mixed with the paper clips. Generate at least 10 data points.
4. Graph data by plotting # broken vs. concentration.
Answer Analysis questions. Staple all analysis questions to graphs and turn in as a group.