Requesting info on digestion

Aaron David Rosenzweig recurve at exp2.wam.umd.edu
Sat Feb 3 19:55:01 EST 1996


I'm sending this on behalf of Jeff Rosenzweig who does not
have a net connection:


I am a 10th grade, High School student who is working on a 
science fair project.  The first part of my project is 
concerned with the digestion of substances in the mouth, 
stomach and small intestine.  While I know which substances 
are digested in the three locations
(mouth, stomach, and small intestine), I would like to learn 
what chemical reactions occurred.

I am trying to find the formula, chemical equations, and 
Lewis Structures for the following:

1.  Amylase (mouth) reaction with potato (carbohydrate)
2.  Pepsin + HCL (stomach) reaction with boiled egg 
whites (protein)
3.  Pancreatin (small intestine) reaction with
A.  boiled egg whites (protein)
B.  butter (fat)
C.  potato (carbohydrate) 

Procedure: for first experiment
-  Added a small sample of the appropriate food to each group 
of test tubes. 
-  Covered each food sample with the appropriate digestive 
solution (amylase, pancreatin, or pepsin).  Added enough so 
that 1/4 to 1/2 of the test tubes are filled.  Inserted 
stopper and placed in a water bath at 37 degrees C. 
-  After 24 hours, examined each tube.  Cloudiness or a 
dissolved food is and indication of enzymatic action.  

The second part of my project was to study how bile salts 
decreased the reaction time when milk reacted with 
pancreatin.

I am trying to find the formula, chemical equations, and 
Lewis Structures for the following:

1.  milk + bile salt + pacreatin
2.  milk + pacreatin

Also, I would like to know why bile salts decreased the 
reaction time.

Procedure: for second experiment
-  Set up 3 test tubes and added 5 mls of whole milk to each.
-  Added 8-10 drops of phenol red solution and shake tubes 
until well mixed.  If the resulting liquid was not pink I 
added NaOH (.l M) drop by drop until pink color remains after 
shaking.
-  To tube #1, add 5 ml of water and a small quantity of bile 
salts (about the amount that would fit on the broad end of a 
flat toothpick).
-  To tube #2, add 5 ml of pancreatin solution and a small 
amount of bile salts.
-  To tube #3, add only 5 ml of pancreatin  solution.
-  Shaked each tube and placed in a hot water bath (37 C).  
Recorded the time.  Watched for color changes (pink to 
yellow) and recorded time of change. 

Thank you for any assistance that you can give me.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you'd like to send me private e-mail that is ok but
consider also posting or at least doing a cc: to the
newsgroup so that others can benefit :-)

recurve




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