Transcript Science Horizons Initiative

Science Horizons
Initiative
Dawn Sturman, Bozeman High School
The Chemistry of Brain-tanning
Animal Hides
The lowdown on dual nature molecules.
Native Americans were resourceful with
using animal parts. Even the brains were
used to tan the animal’s hides.
A deer has enough lecithin in its brain to
tan its own hide???
Say what???
Don’t take my word for it, let’s
check it out!
We have learned that likes dissolve
likes.
If polar compounds dissolve polar compounds
and non-polar compounds dissolve non-polar
compounds, how can the fat in the animal skin
be dissolved and washed away???
Why would you even want to get rid of the fat
in the hide?
Braintanning Lab: Investigating the dual
nature of some molecules.
Materials: hide squares, lecithin, pork or deer brains,
beakers, water, blender, large wooden spoon.
Procedure: Day 1
1. Obtain ¼ cup of blended brain.
2. Put the brain in a 1000ml beaker and cover with water
to the 750ml mark. Mix with a large wooden spoon.
3. Place the hide in beaker. Swish it around with the
wooden spoon to ensure that the entire hide is covered.
4. Leave overnight.
Procedure: Day 2
1. Rinse the hide with lots of water.
2. Wring the hide to get rid of water.
3. Put the hide on a drying rack.
4. Leave overnight.
5. Check the next day and notice how soft it is!
So what happened? How did the brain
mixture dissolve the fat in the skin?
The lecithin, in the brain, is what allowed the fat in the
skin to be dissolved and washed away.
Use these diagrams and styrofoam models, to come
up with an explanation as to how the lecithin
“infiltrated” the skin to dissolve the fat & how it
worked with the water to be washed away.
Discussion:
What is a dual-nature molecule?
What are other uses for dual-nature
molecules?
*Come up with an example and
describe the chemistry involved.
opportunity!
C.W. (Bill) McLaughlin, Ph.D. Director Science Horizons
Initiative & teaching professor Dept. of Chemistry &
Biochemistry
Tess Corbin Dept. of Chemistry & Biochemistry & assistant
director Science Horizons Initiative
Nicole Rae,Ph.D. Dean of Letters and Sciences MSU
Mary Cloninger, Ph.D. Dept. Chair of Chemistry &
Biochemistry
John Peters, Ph.D. Director of T.B.I. & professor of
Chemistry & Biochemistry
Chris Bahn, Ph.D. MSU Department of Chemistry &
Biochemistry
Jamie Cornish, Ph.D. Outreach Specialist Extended
Essential Review
Match the term to its definition.
1. Polar molecule
functional group
a. water-fearing molecule or
2. Non-polar molecule
functional group
b. water-loving molecule or
3. Hydrophilic
c. a molecule with unequal charges
4. Hydrophobic
d. a molecule with equal charges
5. Covalent bond
each other
e. substances that will not dissolve in
in any
proportions.
A Cross-Curricular Activity
with Wildlife Biology
Robin Hompesch, BHS Wildlife Biology teacher, is
designing, with volunteers from the community,
The Brain: Not Just for
Thinking anymore.