Title: The Exploding Liver
By: Doug Coutts
Ministry Expectations:
Big Idea: biological processes, molecules and chemical properties affect cellular
processes and chemical reactions.
B2.4 conduct biological tests to identify biochemical compounds found in various
food samples. (in this experiment alcohol is used)
B2.5 plan and conduct an investigation related to cellular process (eg. Factors that
affect enzyme activity; factors that transport of substances across cell membranes), using
appropriate laboratory equipment and techniques, and report the results in an appropriate
format.
B3.4 describe the chemical structures and mechanisms of various enzymes.
Introduction and Background:
Within the human body there are many chemical reactions taking place at all times.
Chemical reactions involve the breaking and reforming of chemical bonds between
molecules (substrate(s) of the reaction), which are transformed into different molecules.
Within the human body there are constantly chemical reactions taking place that are
producing poisonous products that could seriously harm us. However the body has
proteins called enzymes that can break down these harmful substances into neutral
substances that don’t harm us at all. Enzymes are proteins that are biological catalysts (i.e
they speed up the rate of chemical reactions
Different enzymes act on different substances in the human body. Each enzyme is highly
specific to the particular substrate that is to be catalyzed.
Materials:
1 x protective shield
60 ml 6% Hydrogen peroxide (H2O2)
60 ml 90% ethanol alcohol
1 x 1 liter beaker
Raw Beef Liver
30 cm of magnesium tape
1 x Barbeque Lighter
Safety:
With any highly flammable gases extreme caution must be taken. All students must be far
away from the reaction at all times. A shield must be placed between the students and the
apparatus, reaction and the explosion that occurs. Safety glasses must be worn at all times
while carrying out the experiment. Also when igniting magnesium tape everyone must be
made aware that it cannot be extinguish via water, thus it is advised that there be a
working fire extinguisher that is easily accessible throughout the entire experiment.
Procedure:
1) Make sure that the protective shield is secure and in the proper place and all students
and bystanders are at a safe distance
2) Pour 60 ml of hydrogen peroxide into the 500ml beaker
3) Pour 60ml of 90% ethanol alcohol into the 500ml beaker
4) Carefully place a 30 cm long piece of magnesium tape into the beaker, make sure that
the magnesium tape is in contact the mixture of peroxide and ethanol (tape should reach
the bottom of the beaker)
5) Add some beef liver blood and whole beef liver into the mixture of hydrogen peroxide
and ethanol alcohol mixture, and allow the reaction to occur.
5) Hold the lit barbeque lighter to the bottom of the magnesium tape until the magnesium
tape ignites
6) Stand far away form the beaker after the magnesium tape is lit, make sure that all
students are at a safe distance form the beaker and protective shield.
7) After the explosion wait a few minutes to make sure than all reactions are complete.
Then dilute the mixture with water and dispose of properly.
Results:
When the burning magnesium tape reaches the gases produced by the reaction of liver
and the hydrogen peroxide/ethanol alcohol mixture the gases explode.
Explanation:
Catalase is a common enzyme found in nearly all-living organisms exposed to oxygen. It
catalyses the decomposition of hydrogen peroxide to water and oxygen. When the
Catalase reacts with hydrogen peroxide tiny bubbles are form, this is how you can tell by
eye that the reaction has occurred. Within these bubbles oxygen is contained (Catalase,
2012).
Alcohol Dehydrogenase is an enzyme found in humans and many other organisms, which
serves to facilitate the interconversion between alcohols and aldehydes or ketones with
the reduction of nicotinamide adenine dinucleotide (NAD+ to NADH). In simpler terms
this enzyme serves to aid in the breakdown of alcohols that are otherwise toxic, and they
also participate in generation of useful aldehyde, ketone, or alcohol groups during
biosynthesis of various metabolites (Alcohol Dehydrogenase, 2012).
This reaction itself releases both acetaldehyde and hydrogen. Both substances are very
flammable and contribute to the combustion reaction. These to chemicals get trapped in
the foam that is produced by the reaction of Catalase and hydrogen peroxide. Thus when
the magnesium flame hits the bubbles they explode.
Tips for Success/Teacher Notes:
1) Make sure that all teachers and students in classes close to the class that you are
doing the experiment in are made aware that they may hear a minor bang when
the gases are ignited.
2) With any explosive reaction safety always comes first. Thus as preparation inform
the students this experiment is dangerous and no horse play will be tolerated
3) Relate the content to the real world.
4) Make sure that you use fresh liver, so to minimize breakdown of important
enzymes.
5) Advise all parties that they should not look directly at the ignited magnesium
ribbon.
References:
Alcohol dehydrogenase. (2012, March 19). In Wikipedia, The Free Encyclopedia.
Retrieved 18:33, March 28, 2012,
from http://en.wikipedia.org/w/index.php?title=Alcohol_dehydrogenase&oldid=48263
3918
Catalase. (2012, March 24). In Wikipedia, The Free Encyclopedia. Retrieved 18:34,
March 28, 2012,
from http://en.wikipedia.org/w/index.php?title=Catalase&oldid=483700408
Youtube Video Of Demonstration
http://www.youtube.com/watch?v=hR38o2Ec8b0