Grade Level/Subject
Chemistry grades 10 -12
Unit
This is a culminating activity that should be attempted after Unit 8
(Biochemistry)
I. Student will investigate and understand how basic chemical
properties relate to organic chemistry and biochemistry
II.
Measurements are useful in gathering data about chemicals and
how they behave
III.
Techniques for experimentation involve the identification and
proper use of chemicals and description of equipment
IV. Carbon’s tetra valence allows for macromolecules
Enduring Understanding
SOL Standards
CH. 1, CH.6
Title
Enzyme investigation
Lesson Objective
Inquiry Level
Materials Required
I.
II.
III.
IV.
V.
3
Students are to design and conduct an experiment exploring the
role of enzymes in laundry detergents
Students will collect, record, analyze and discuss data
Students will recognize proteins as important polymers
Student will perform multiple trials
Student will manipulate multiple variables and make perdictions
Multiple laundry detergents (with and without enzymes), scrap material
cut in pieces, food, markers, misc. for staining material
Enzyme Investigation Inquiry Lab
Enzymes are catalysts…
A catalyst is a chemical substance that affects the rate of a chemical reaction by altering the activation energy required
for the reaction to proceed. This is called catalysis. A catalyst is not consumed by the reaction and it may participate in
multiple reactions at a time. The only difference between a catalyzed reaction and an uncatalyzed reaction is that the
activation energy is different. There is no effect on the energy of the reactants or the products. The ΔH for the reactions
is the same.
Positive and Negative Catalysts
Usually when someone refers to a catalyst, they mean a
positive catalyst, which is a catalyst which speeds up the rate
of a chemical reaction by lowering its activation energy. There
are also negative catalysts or inhibitors, which slow the rate of
a chemical reaction or make it less likely to occur.
Promoters and Catalytic Poisons
A promoter is a substance that increases the activity of
catalyst. A catalytic poison is a substance that inactivates a
catalyst.
How Catalysts Work
Catalysts permit an alternate mechanism for the reactants to
become products, with a lower activation energy and
different transition state (crest of the graph). A catalyst may allow a reaction to proceed at a lower temperature or
increase the reaction rate or selectivity.
Most enzymes are proteins, and proteins are a
macromolecule made possible by the tetra
valence of carbon.
PROTEINS are a string of amino acids. AMINO ACIDS Central (α carbon) with CARBOXYL,
AMINO, H, and R groups attached. There are 20 common amino acids used by all living
things; lys-arg-his-asp-glu-ala-val-leu-ile-pro-phe-met-trp-gly-cys-ser-thr-tyr-asn-gln
k- r- h- d- e- a- v- l- i- p - f - m- w- g-c - s -t - y–n- q
Enzymes lower activation energy – thus a reaction will need less activation energy
in order to proceed.
Investigation:
In this investigation you are going to explore the role of enzymes in cleaning laundry. You will be provided with multiple
samples of laundry detergent, several types of fabric and several stain making ingredients.
You are to design and conduct an experiment to demonstrate the difference between the detergents with and without
enzymatic action. Record all plans, procedures, and data collected in you lab books. Color photos or drawings are
helpful. Be prepared to discuss your findings with the class.
Questions:
I.
II.
Why do you think some stains could be removed and some could not? Explain your logic.
What are some other variables you may want to change and why?
Safety
Remember you are working with chemicals. Follow all safety procedures issued by your teacher. Note: soap in your
eyes sting! Wear goggles.
If you pour a handful of salt into a
full glass of water, the water level will actually
go down rather than overflowing the glass.