HOLIDAY SPIRIT REACTION
Katharine M. Noonan
Oakland High School
1023 MacArthur Blvd.
Oakland, CA 94610
Type of Activity:
Artwork, modeling, multicultural
Biology, Advanced Biology
This activity gives students a chance to work through and personalize their understanding
of enzyme function. It is an opportunity to be creative and celebrate diversity.
: Students should know that enzymes are protein catalysts which facilitate and control
all of the chemical reactions of life. They should know that enzymes work by combining
temporarily with their substrates to bring about favorable orientation for the formation of a chemical bond between the substrates. The idea that the function of
an enzyme depends on its shape will emerge in this activity.
Moderate. I make a large cardboard model of the HolidaySpirit molecule, the Love
enzyme, and the separate substrates Holiday and Spirit to show students when I introduce
the activity. I suspend the models from the ceiling for the duration of the activity.
For students, you need to run off the directions for the project (follows), strips
of 8" X 14" construction paper, scissors and paste, holiday paper of various types
(the more diverse, the better). Ask students to bring in gold or white paint pens
to label molecules cut out of non-solid paper. Markers for labeling.
Class time needed
for this activity is 2-3 class periods (shorter for more advanced groups).
Students invent an enzyme and its substrates, using a holiday motif. They make
a paper "story strip" to show how their enzyme catalyses the formation of its product.
This gives the opportunity for one-on-one interaction between teacher and student
as each student "acts out" his/her reaction for the teacher before pasting. Comparison
of different student's work underscores the specificity of enzyme action and the
importance of shape.
1. Introduce the project using cardboard models to act out the Holiday Spirit Reaction.
2. For homework, ask students to think of a holiday molecule and an enzyme they would like to illustrate. If you have them, post some examples from previous years, or
make a model story strip yourself, but emphasize that students should be creative
and may celebrate their culture if they wish. You can decide how outrageous they may be.
I have my limits. One year I had a drug-related reaction, which I graded for accuracy,
but did not display. I had a Kevorkian enzyme catalyzing successful suicide molecules (I didn't post that one, either).
3 . As students work, move around the room admiring choices of holiday molecules,
enzymes, paper, shapes (I had a turkey-shaped enzyme catalyzing ThanksGiving molecules
one year.) Ask students to show the steps of the reaction for you. They should
be able to do this and identify terms in their model before they are allowed to paste.
4. Display the different story strips. Students enjoy seeing each other's work
and being recognized for their own creativity.
5. Lead a discussion about the assembled story strips. Ask if the enzyme from one
strip could catalyze the reaction on a different strip. What determines the shape
of an enzyme? What would happen if a molecule similar to the enzyme's substrate
stuck onto the active site and didn't fall off? (Noncompetitive inhibition). What if something
attached to the enzyme and distorted the shape of the active site? (allosteric inhibition).
What if there were other molecules which, like the real substrates, could attach briefly to the active site, but fell away without forming the product? (competitive
Grade story strips for completeness and accuracy, neatness and creativity.
HOLIDAY SPIRIT REACTION
Enzymes are protein molecules that help other molecules (substrates) react together
(or break apart). They have active sites which hold the substrates in position so
that a chemical bond can form between them with less activation energy. The combination
of an enzyme and its substrate is called an enzyme-substrate complex. Once the bond
is made, the enzyme-substrate complex breaks up. The joined substrates (now called
the product) leave the enzyme. The enzyme is now free to help another pair of substrates bond together.
Let's visualize this process by making a model with a holiday motif. Our product
will be HolidaySpirit (or any two-word holiday phrase you choose: HabariGani (Kwanzaa),
FelizNavidad, ProsperousNewyear, MerryChristmas, HappyHanukkah, etc.). What is
it that helps produce this holiday feeling for you? Love? Friendship? Peace? These things
help create the holiday feeling but are not used up! Choose one (e.g. Love) to be
Draw your combined enzyme and substrates
to the right. This is the enzyme-substrate complex.
Write the names you have chosen for the enzyme,
and product on the drawing. Using your drawing
as a pattern cut out 5 enzyme shapes of one color,
and ten of each substrate shape using different colors.
Obtain a 8" X 14" strip of construction paper and fold it into 4 frames. Arrange
your shapes to illustrate the enzyme-catalyzed reaction. CHECK WITH YOUR TEACHER
BEFORE YOU DO ANY PASTING OR PERMANENT WRITING. Write these captions below each
frame, and put in arrows and labels to show substrates, enzyme, active site, and product.
Frame 1: The substrates (e.g. Holiday and Spirit) can't react together by themselves.
They bump together in ways that do not fit. They have too little or too much energy
to form a bond. No HolidaySpirit (or your choice) is produced.
Frame 2: The substrates attach to the active site on the enzyme (arrows).
Frame 3: An enzyme-substrate complex is formed. Now the substrates (Holiday and
Spirit) can react together. The (Love) enzyme holds them in the correct position.
Frame 4: After the product (HolidaySpirit) forms, it falls off of the enzyme. The
enzyme is then free to help new substrate molecules to form the product. (Show the
product leaving the active site of the enzyme and 2 new substrates coming to the
empty active site on the enzyme. Show several product molecules that have been made earlier
by the enzyme.)