Requesting info on digestion

Aaron David Rosenzweig recurve at
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 

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 
-  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 :-)


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