Download Document

Biology
Building Organic
Compounds
Student Page
Enduring Understandings
Nutrients passes through organisms and the environment through
biogeochemical (carbon-oxygen and nitrogen) These cycles are critical for
life.
Carbon can bond with many elements, including hydrogen, oxygen,
phosphorus, sulfur and nitrogen to form molecules of life.
Vocabulary
Monomer, polymer, biomolecule, macromolecule, carbohydrate, protein,
lipid, nucleic acid, monosaccharide, amino acid, glycerol, fatty acid,
nucleotide
Essential Questions:
Topical Questions:
How does matter and energy flow through ecosystems?
What is the role of biomolecules in organisms?
Objectives
Compare the structure and function of different types of bio-molecules.
BACKGROUND INFORMATION:
Carbohydrate, lipids and proteins and nucleic acids are three major groups of organic chemicals that make up
cells in organisms. They are responsible for everything from the storage of energy to support structures within
a cell system. The chemical elements carbon, hydrogen, oxygen, phosphorus, sulfur and nitrogen in different
combinations, make up each of the molecules. How these elements are arranged dictates the type of
molecule that’s formed.
All organic compounds have a single basic building unit called a monomer. Monomers are put together to
make variations and different forms of each organic compound. For example, the monomer of a carbohydrate
is a monosaccharide (a simple sugar). Monosaccharides are bonded together to make other carbohydrates,
such as disaccharides and polysaccharides. Whenever two monomers are bonded together to make a new
compound, a process called dehydration synthesis occurs. Dehydration synthesis is a type of synthesis
reaction in which two smaller molecules are joined together by a covalent bond and water is formed (released)
in the reaction. This is the opposite of hydrolysis, in which water two hydrogens and an oxygen is added back
to the molecules as they are broken apart. The formation of sucrose from glucose and fructose is an example
of dehydration synthesis. Glucose + Fructose => Sucrose + Water
MATERIALS
Gumdrops of 4 different colors: 24 Carbon, 50 Hydrogen, 9 Oxygen and 4 nitrogen
Handout
Textbook
Toothpicks
Pencil
PROCEDURE
Work in groups of 3 or 4 to complete this activity.
Carbohydrates:
Each member of the group will construct a glucose molecule on their own according to the drawing provided.
After each molecule is made, the group will come together and follow the instructions and answer the questions
regarding carbohydrates.
Lipids:
One member of the group will construct the glycerol molecule and the remaining members will construct the fatty
acids using the diagram provided. Once these parts are completed, the group will come together and follow the
instructions and answer the questions regarding lipids.
Proteins:
Each member of the group will construct one of the three to four amino acids on their own according the diagram
provided. After each molecule is made, the group will come together and follow the instructions and answer the
questions regarding proteins.
updated 10/06/2010
1
Each group needs to write the designation of each colored gumdrop to each element used: carbon, hydrogen,
oxygen and nitrogen. Write this key using the elements in the materials section of this paper.
Part I. Carbohydrates-follow the instructions above to complete carbohydrates.
H
C
H
H
OH
C
C
OH
HO
H
O
H
H
C
C
H
OH
C
OH
1. How many are in your group?
2. If you were to make a more complex carbohydrate, explain how this would happen.
3. Perform dehydration synthesis with all of the molecules your group has made. Be sure to assemble the
resulting water molecules. Call the teacher and get your polymer approved. _______
4. Is the resulting compound a sugar or a starch? Explain.
5. How many glucose molecules did you start with?
6. How many water molecules did you end up with?
7. What is the connection between the number of monomers you started with and they number of water
molecules you ended up with?
8. What type of chemical bond is holding the glucose molecules in place?
9. Now perform hydrolysis to your polymer. Call the teacher to have it checked. _______
10. How many water molecules must you add back. Why?
12. How does your body store excess sugars? How does a plant store excess sugars?
updated 10/06/2010
2
Part II. Lipids- follow the instructions above to complete lipids.
H
H
C
OH
HO
Glycerol
H
H
C
C
H
OH
OH
HO
HO
O
H
H
H
H
H
H
C
C
C
C
C
C
C
O
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
O
H
H
H
H
H
H
H
H
H
H
H
H
C
C
C
C
C
C
C
H
H
H
H
H
H
H
Fatty Acid Tail
H
H
1. Once the glycerol and fatty acids have been constructed, the glycerol and fatty acids need to be bonded
together. To do this, place the glycerol molecule in front of you so the functional groups are located on the
right. Place the three fatty acids to the right of the glycerol, oriented so the functional group ends are near the
functional groups of the glycerol. Remove the hydrogen atom from each functional group of the glycerol.
Remove the –OH group from each fatty acid. Join each fatty acid to the glycerol to produce a triglyceride
(lipid). Call your teacher to have it checked. _______
2. What process occurred as you bonded the glycerol to the fatty acids? Is your completed molecule a
triglyceride? How do you know?
3. How many carbon, hydrogen, and oxygen atoms are in your completed lipid molecule?
4. Energy available to an organism is stored within the carbon-hydrogen bonds of molecules. Oxygen atoms
may intervene between carbon and hydrogen atoms, causing a decrease in the energy available. Therefore,
the less oxygen present per hydrogen atom, the more energy is stored within a molecule. Examine the ratio of
carbon to hydrogen to oxygen in a carbohydrate and in a lipid. According to your observations, which
substance stores more energy, carbohydrates or lipids, and what is your evidence to support your answer?
5. The following represents the general equation for producing a triglyceride:
__________ + __________
a triglyceride + ___________
-Fill in the names of the reactants to indicate what two sub-units make a triglyceride.
-Fill in the product to show what else is released when a triglyceride is made.
-How many of these second products are produced?________
updated 10/06/2010
3
Part III. Proteins – follow the instructions above to complete proteins
H
H
O
H
N
C
H
C
H
C
H
N
OH
H
O
H
H
C
C
H
OH
Alanine
Serine
H
C
H
N
OH
H
O
H
C
H
H
N
C
OH
Glycine
H
O
H
C
C
OH
R
General
Structure
1. Once each amino acid has been made, they need to be bonded together. Place the glycine model next to
the alanine model. Remove the –OH (including the toothpick) end from the functional group of the glycine.
Remove a hydrogen atom (including the toothpick) from the functional group on the left of the alanine. Bond
the glycine to the alanine at these locations. Repeat this process to add Serine to your chain.
2. What elements are left over from this bonding process? What process occurred during the bonding of the
amino acids?
3. What type of bond was formed when combining amino acids to make a protein?
4. Identify the three major roles of proteins.
updated 10/06/2010
4