Constructing Organic Macromolecules (Polymers)
from Building Blocks (Monomers) and Simulating
the Reaction of Dehydration Synthesis
Instructions
 Use the information below to complete the chart on
your notes page.
 Highlight information you transfer to your chart
 Follow the instructions below to construct molecular
models of the building blocks (monomers) described.
 Follow the instructions below to construct
macromolecules (polymers) by joining the monomers
you made in step 2 using the process of dehydration
synthesis. Be sure to show your teacher how

these monomers combine.
Answer the questions on your own sheet of paper to
turn in.
Carbohydrates
Carbohydrates are organic compounds that are
present in all organisms in various forms. They can exist
as monomers known as monosaccharides (simple sugars).
The monomers can also link together to form disaccharides
(2 monosaccharides linked together; example: sucrose or
table sugar). Finally, organisms also have carbohydrate
polymers known as polysaccharides or complex
carbohydrates. These are made by linking many
monosaccharides together; an example is starch. The
principal elements of carbohydrates are carbon, hydrogen,
and oxygen, and (rarely) nitrogen. The C, H, and O are
present in a 1:2:1 ratio.
Functions of carbohydrates include providing
organisms with energy and with structural support, such as
in the cell walls of plants and fungi. Besides starch, other
examples of polysaccharides or complex carbohydrates are
glycogen, cellulose, and chitin. Starch, which is produced
by plants, and glycogen, which is produced by animals, are
stored forms of energy. Starch and glycogen can be
broken down into the monosaccharide glucose, which is a
readily usable energy source. Some sources of starch
polysaccharides are cereals, bread, fruit, and vegetables.
Using the figures as a guide, perform the following steps:


Construct a single glucose molecule (a monomer
known as a monosaccharide).
Locate a classmate who has also assembled a
carbohydrate monomer, and join your monomer
with theirs to create disaccharide, the beginning of
a carbohydrate polymer. Note the atoms that are
left over as a result of the disaccharide formation.
Glucose – a
monosaccharide
1. After the two glucose molecules join to form a
disaccharide, what molecule do the atoms left over
form?
2. What are the subunits (monomers) for carbohydrates?
3. How is a polysaccharide formed from the above
disaccharide?
Lipids
Lipids are a group of organic compounds that are
mostly insoluble in water (hydrophobic), but are soluble in
non-polar organic solvents. Some important families of
lipids are fats, phospholipids, and steroids.
Fats are large molecules assembled from two kinds
of smaller molecules, glycerol and fatty acids. Glycerol is a
molecule consisting of three carbons, each bearing a
hydroxyl (OH) group. A fatty acid consists of a long chain
of carbon atoms (16 – 18 carbons), called the “tail.” At
one end of the fatty acid is a “head” consisting of a
carboxylic acid group (COOH), the functional group of the
molecule that gives these molecules their name of “fatty
acids.”
Lipids serve as a concentrated source of energy
and provide thermal insulation and structural components
of shock-absorbing pads for organs, bones, and muscles.
In addition, lipids play an important role as structural
components of cell membranes.
The principal elements in lipids are carbon,
hydrogen, oxygen, and perhaps nitrogen and phosphorus.
Unlike carbohydrates, the C, H, and O molecules are not
present in a 1:2:1 ratio. Some sources of lipids are nuts,
butter, vegetable oils, and cheeses.
Using the figures as a guide, perform the following steps:


Construct either a glycerol molecule or a fatty acid
chain, as instructed by your teacher.
Locate classmates who have constructed glycerol
or fatty acid molecules, and use dehydration
synthesis to form a triglyceride molecule.
Fatty
acid
+ H2O
7. What are the subunits (monomers) that make up
proteins called?
8. How are the monomers joined together to form a
protein polymer?
9. What are the atoms and functional units of amino
acids?
4. How many times does the reaction of dehydration
need to occur to construct a triglyceride from a
glycerol molecule and the fatty acids?
5. How many glycerol models does it take to form a
triglyceride model?
6. Describe the structure and functional group of a fatty
acid.
Proteins
Every cell in your body contains many proteins.
Proteins have a number of very integral functions in living
organisms. These functions include the growth,
maintenance and repair of tissues. They are also form
important parts of the structures of enzymes, hormones,
and antibodies. The principal elements found in proteins
are carbon, hydrogen, oxygen, nitrogen, and usually sulfur.
All proteins are polymers made out of building
blocks (monomers) called amino acids that link together
into long chains. The chains are called peptide chains.
These chains then often coil and fold into complex shapes.
There are 20 different amino acids. The function and
properties of any given protein are determined by which
amino acids have linked to form a chain (a chain may be
from 50 to 50,000 amino acids long), and also by the
shape and structure of the final protein polymer. Sources
of proteins include milk products, eggs, meat, fish and
beans.
An amino acid consists of a central carbon atom
(called the alpha carbon) bonded to an amino group (NH2),
a carboxyl group (COOH), a hydrogen atom, and a
distinctive R group (each amino acid’s R group has its own
unique molecular components). Glycine is the simplest
amino acid. Its R group is simply a hydrogen atom.
Using the figure as a guide, perform the following steps:
 Construct a single amino acid molecule (a
monomer for proteins).
 Locate a classmate who has also assembled an
amino acid monomer, and join your monomer with
theirs to form the beginnings of a protein polymer.