Download Cut and Paste Macromolecule Instructions

The reverse of this process is known as hydrolysis, and in living systems, involves enzymatic activity that
results in adding a water molecule back in to hydrolyze the bond that formed to join the individual monomers
together in the first place.
You will model both of these processes using paper models of the monomers used to construct biomolecules.
Part One: Molecules for Cell Energy and Structure—Carbohydrates and Lipids.
Directions for assembly: Carbohydrates
1. To build carbohydrates, monosaccharides are needed. Obtain
two glucose monomer papers (one for each lab partner) and
number the carbons like this:
Numbering the carbon atoms is important so you can determine
where the bonding of monomers will take place.
2. Now you will form a disaccharide. Join (bond) your two
glucoses together by cutting off and -H- from one molecule and an
-OH- from another and taping the 2 molecules together forming a
glyosidic bond. Give your disaccharide a name, bearing in mind
that sugar names end in “-ose” (glucose, fructose) and write that
name on the bottom of the molecule.
3. Then take the trimmed H-O-H, glue it to the water drop and tape/glue the water drop onto the bond. Your
finished product may look something like this.
4. Now, take the disaccharide you have created, and bond it in the same manner with another pair of students
and their disaccharide using the same paper dehydration synthesis process. Give your polysaccharide a new
name, remembering that it too must end in “—ose.” Write that name on the top of the molecule.
Directions for assembly: Lipids
1. To build lipids, glycerol and fatty acid chains are needed. There are two types of fatty acid chains:
a. Saturated: these fatty acids have no double bonds along the carbon backbone
b. Unsaturated: these fatty acids have at least one double bond along the carbon backbone
Obtain a glycerol paper and three different saturated fatty acid papers. You will first build a saturated fat, and
then an unsaturated fat.
2. Take one glycerol molecule and three differently colored saturated fatty acid molecules and join them by
cutting off an –H– from one molecule and an –OH– from another and taping the two molecules together
forming an ester bond. Label this bond.
3. Then take the trimmed H-O-H, affix it to the water drop, and tape the water drop onto each ester bond.
4. Repeat this process to build an unsaturated fat, except use an unsaturated fatty acid paper in place of one
of the saturated fat papers.
Answer the following questions in complete sentences on a separate sheet of paper.
1. Describe the process of dehydration synthesis.
2. Give a biological function for each of the following molecules, with a named example of each:
a. Carbohydrates
b. Lipids
3. Where in a cell would long-chain carbohydrates be synthesized, and by what organelle? During what
cellular process would this occur?
4. How does putting a double bond in the carbon chain of a lipid affect the structure of the fatty acid?
5. Based on what you have observed about lipid structure, could a lipid be considered a polymer? Why
or why not?
6. What organelle in a cell is responsible for lipid synthesis?
7. Based on the structure of carbohydrates and lipids you have observed, explain which molecule is
better suited for long-term energy storage and why you think this.
Part Two: Molecules For Cell Structure, Transport and Regulation—Proteins (polypeptides)
Directions for Assembly: Proteins
1. To build a protein, use at least 5 of the amino acid papers your teacher gives you.
2. Once you’ve got your amino acids selected, you will need to use your textbook to find out whether or not the
amino acids you have been assigned are charged or uncharged, polar or nonpolar. Then, write the name and
the chemical characteristic on each amino acid paper. This will help you to determine how the amino acid will
behave once it is assembled into a protein.
3. Now, join your amino acids together by cutting off an –H– from one molecule and an –OH– from another and
taping the two amino acid molecules together to form a peptide bond.
4. Then, take the trimmed H-O-H, affix it to the water drop, and tape the water drop onto the peptide bond.
Your finished product may look like this:
Note: This is a very short polypeptide and that proteins in biological systems can be hundreds or even
thousands of amino acids long.
5. Now that you know how proteins are formed, it’s time to fold them based on the chemical properties of their
constituent amino acids. Remember that polar amino acids will orient themselves to the outside of the
molecule so that they interact with the aqueous environment of the cell, while nonpolar amino acids will orient
themselves toward the inside of the molecule to avoid contact with the aqueous environment of the cell. If your
protein has sulfur atoms, disulfide bridges may form. If your protein has amino acids with positively charged
and negatively charged regions, then you may have ionic bonding taking place as well. This will cause the
amino acids with opposite charges to be attracted to one another.
6. Give your newly formed protein a name. The naming convention for proteins is such that protein names
typically end in the suffix “—in.”
Answer the following questions in complete sentences on a separate sheet of paper.
1. Give a biological function for each of the following molecules, with a named example of each:
a. Proteins
b. Nucleic Acids
2. What effect on protein structure do the following have:
a. Nonpolar amino acids
b. Polar amino acids
3. Why is this paper model not the best representation of protein structure? Name and describe the
levels of protein structure that are missing.