Download Food Chemistry

General Biology
Name: ____________________________ Block: ___________ Group: ___________
Food Chemistry and Identification
Building your Digestive System Board
Parts to be included on your boards:
Nutrients
Organs
Carbohydrates: Starch
Cellulose
Protein
Fats
Water
Mouth
Salivary Glands
Pharynx
Esophagus
Gall Bladder
Liver
Stomach
Pancreas
All three parts of the small intestine
All parts of the large intestine
Cecum
Appendix
Rectum
Anus
Put an enlarged cell near the heart
1. Show all of the organs from the list on your board (you can not label them on your
board).
2. Show nutrient particles in the following places;
a.
b.
c.
d.
e.
f.
g.
h.
i.
Outside of the mouth
Esophagus
Stomach
Small Intestine
Large Intestine,
Rectum
Out of the anus
Going through the circulatory or lymphatic system to the cell near the heart
Inside your cell near the heart
3. Know what enzymes are involved in the digestive process.
4. Know where the enzymes are found and what nutrient they break down.
5. Know what the function of each nutrient is.
6. Add the heart and lungs along with a cell to your diagram board.
7. Show the circulation from the intestines to the cell to the heart to the lungs.
8. Show arteries and veins in circulatory pattern and also lymphatic path.
9. Show respiration following the pathway of oxygen and carbon dioxide in the
breakdown of glucose.
Nutrients
1. Water: Through the digestive tract and some is absorbed by the large intestine and the
remaining goes out the anus. We consume it to prevent dehydration, aid in chemical
process, to dissolve things, and to cool you down.
2. Cellulose: Goes through the whole system and out the anus. Provides us with bulk, or
roughage. Roughage, or fiber, stimulates the muscle of the stomach and intestines. This
makes our digestive system work more efficiently.
3. Fats: Goes through the mouth and pharynx and esophagus and stomach. Enters the
small intestine where the enzyme “pancreatic lipase” transforms fats into glycerol and
fatty acids. After the small intestine, it enters the lymphatic system and through the
lymphatic system it enters the blood and is carried to the cells.
4. Proteins: Through the mouth and the esophagus. Enters the stomach and “pepsin”
breaks protein into dipeptides. Then enters the small intestine and “carboxypeptidase”
break dipeptides into amino acids. The amino acids then enter the blood stream and enter
the cell, where it goes to the ribosome to provide the body with the building material it
needs for growth and repair.
5. Starch: Enters the mouth where salivary amylase “Ptyalin” breaks it down into the
disaccharides called Maltose. Maltose travles down the esophagus and into the stomach
and enters the small intestine where “maltase” works on it. Maltase breaks maltose down
into the monosaccarides called glucose. The simple sugars are then taken by the blood
stream and carried to the cell where the simple sugars go to the mitochondria where it
then performs respiration. Respiration requires oxygen, releases carbon dioxide, and
produces large amounts of ATP. Cells use respiration to produce energy.
Digesting Foods
You are probably already aware that food is digested as it travels down into your body.
Turn to page 867 in your textbook and draw the digestive system.
What does the term digestion mean?
________________________________________________________________________
Where does digestion begin? ________________________________________________
Part I: Water
1. What is the chemical formula for water? _____________________________________
2. Add water to your model showing the process of digestion, think about where water is
absorbed and where it is found in the body.
Part II: Carbohydrates
There are three different groups of carbohydrates. They are called monosaccharides,
disaccharides, and polysaccharides. “Saccharide” means sugar.
Monosaccharides (single molecule sugars)
A single molecule sugar is called a monosaccharide. The prefix “mono” means one.
However, the one molecule can have different shapes due to a different arrangement of
atoms. Three monosaccharides are glucose, fructose, and galactose.
Examine the structural formulas of these three sugars; if you need to, build the models
with the organic model sets available.
1. What three elements are present in the three monosaccharides shown?
________________________________________________________________________
2. How many atoms of carbon are present in each molecule?
________________________________________________________________________
3. Indicate the chemical formula for each sugar.
________________________________________________________________________
4. What functional groups are found in carbohydrates? ___________________________
5. Are glucose and fructose exactly the same in shape? Explain.
________________________________________________________________________
6. What do we call compounds that have the same chemical formula but different shapes?
________________________________________________________________________
Disaccharides (double molecule sugars)
Two monosaccharide sugar molecules can join chemically to form a larger carbohydrate
molecule called a double sugar, or disaccharide. The prefix “di-“ means two. By
chemically joining a glucose molecule with a fructose molecule, a double sugar called
sucrose is produced.
Cut out a model of one glucose molecule and one fructose molecule, cut along the solid
lines only!
1. Do the glucose and fructose fit together easily to form a sucrose molecule? _________
2. In order to join the molecules, remove an –OH end from one molecule and an –H end
from another. Cut along dotted lines.
3. Does removing the –H and –OH ends now allow the molecules to fit together easily?
4. The –H and –OH ends that were removed can also fit together with each other to form
a molecule. This new molecule has a simple formula of ______ and is called ________.
5. Write the simple formula for sucrose by adding together the molecular formulas for
glucose and fructose and then subtracting water. __________
6. Different disaccharide molecules can be made by joining other monosaccharides in
different combinations. By chemically joining a glucose molecule with another glucose
molecule, a double sugar called maltose is formed.
7. Cut out and attempt to join the two new glucose model molecules.
8. What must be removed from the glucose model molecules to that they easily fit
together? ___________
9. Write the simple formula for maltose. _________________
10. How does the simple formula for sucrose compare to maltose? _________________
Polysaccharides (many molecule sugars)
Just as double sugars were formed from two single sugar molecules, polysaccharides are
formed when many single sugars are joined chemically. The prefix “poly-“ means many.
Starch, glycogen, and cellulose are the three most common polysaccharides in biology.
They consist of long chains of glucose molecules joined.
Construct a starch molecule by joining the six glucose molecules. This model will
represent only a small part of a starch molecule because starch consists of hundreds of
glucose molecules.
1. What must be removed from the glucose model molecules in order to have them easily
fit together? ___________
2. Add cellulose and starch molecules to your digestion board.
Part III: Proteins
Proteins are complex molecules made up of smaller molecules called amino acids. There
are twenty different amino acids found in nature that life utilizes. The element nitrogen is
present in all amino acids.
Examine the structural formulas of the four representative amino acids shown below.
1. What elements are present in these amino acids? ______________________________
2. What functional groups are found in amino acids? _____________________________
Combining Amino Acids to form Protein
Amino acids are not protein molecules. They are only the “building blocks” of protein.
Several amino acids must be chemically joined in a chain to form a protein molecule.
We can show how amino acids join by using models.
Cut out the four amino acid models. Cut along the solid lines only!
1. Attempt to join the amino acids. Can the amino acid models easily join to form a
protein molecule? ____________
2. Join the molecules by removing as many –OH groups and –H groups as needed from
the amino acids. All four amino acid molecules can be joined in this manner to form a
protein. Join them in the order valine – thronine – alanine – glycine join the leftover
–OH and – H ends.
3. What chemical substance is formed when the –OH’s and –H’s are joined? _________
4. How many molecules of water are formed when four amino acids join? ________
5. What chemical compound is formed when the four amino acids are joined? _________
6. Describe the differences between an amino acid molecule and a protein molecule.
________________________________________________________________________
________________________________________________________________________
There are thousands of different proteins in living organisms. What makes each protein
different is the order, number, kind, and arrangement in space of amino acids joined.
You only assembled four amino acids into a protein using a specific sequence.
7. Construct two protein different from the one you made above. List the order of amino
acids;
(a) ___________________________________________________________
(b) ___________________________________________________________
8. How many different sequence arrangements are possible with just these four amino
acids? ______________ What about with all twenty amino acids? _____________
9. Add protein to your digestion board.
Part IV: Fats
To better understand the chemistry of fats, it is helpful to study first the small molecules
which join to make up fats. Fat molecules are made up of two small “building blocks,”
or chemical molecules. These molecules are called glycerol and fatty acids.
Here is a structural formula of glycerol;
1. What elements are present in glycerol? ______________________________________
2. Are there any elements in glycerol that are not in carbohydrates? _________________
3. What functional group is found in glycerol? __________________________________
Fatty Acids
The second kind of molecule which is part of a fat is a fatty acid. Many different fatty
acids exist, but all are similar in several ways. Butyric acid, caproic acid, and lauric acid
are examples of fatty acids. Study the figure below showing the structural formulas for
these three fatty acids.
1. How do they compare? __________________________________________________
2. What functional group(s) can you identify? __________________________________
Combing Glycerol and Fatty Acids to Form Fat
A fat molecule consists of one glycerol molecule and three fatty acid molecules joined.
Cut out the glycerol and fatty acid paper model molecules. Cut along the solid lines
only!
1. Will the fat molecule fit together as pieces in a puzzle? ________
2. Remove three –OH ends from the glycerol molecule and three –H ends from the fatty
acid. Now join the molecules to form a fat.
3. How many glycerol molecules are needed to form a fat molecule? _______ How many
fatty acid molecules are needed to form a fat molecule? __________.
4. Join the leftover –H and –OH ends from your models, what does this make? ________
5. What is the name of the process that removes water to make macromolecules?
_________________________ In order for this process to take place a
_________________________ must be present.
6. Add fat to your digestion board.