Building Monomers of Macromolecules
Introduction:
The term macromolecule by definition implies "large molecule". In the context of biochemistry, the term may be applied to the four large molecules that make up organisms --- nucleic acids, proteins, carbohydrates, and lipids. Macromolecules are made of smaller subunits called monomers. We will construct the monomers that make up the larger polymers (macromolecules).
Objective:
Students will construct the basic components of organic molecular structure (monomers)
Materials:
Introductory Molecular Model Set
Task:
Construct each of the following monomers and answer the questions. After constructing each monomer, bring your lab sheet & model to the teacher to be approved and then break them down so the next model can be made.
REMEMBER:
1. Molecules are 3-dimensional so models will NOT ALWAYS BE FLAT!
2. When constructing a functional group (-OH, -COOH, -NH2)
PUT BONDS BETWEEN ALL ELEMENTS!!
3. Black = C Red = O Blue = N White = H
4. Short light grey links = single covalent bonds
Long darker grey links = double bonds
DO NOT USE WHITE LINKS
Bonds
Complete the data table by examining each type of atom and recording the information. The number of bonds the element can form can be determined from the number of holes in the model representing it.
Element / Number of bonds it can form / Group Number on periodic tableC
H
O
N
The elements in the data table above are some of the elements found in organic molecules. Organic means that the molecule has carbon in it.
Read pages 166 – 167 in your text.
1. Why do you think carbon is the “backbone” of organic molecules? Look
at how many bonds it can form. Why is that useful?
2. What type of bonds will carbon form with the other elements?
Construct a methane molecule
Methane (CH4) is an organic molecule called a hydrocarbon. It is not a monomer of the macromolecules we will study, but it is a simple organic molecule. If you remove one H and replace it with a C, notice that you can make many branches or chains or rings using carbon and
hydrogen. This is why carbon is so special!
Macromolecule: Carbohydrate
Monomer : Monosaccharide
Read page 168 in your text.
Construct a monosaccharide (glucose).
1. What is the chemical formula for glucose? (CHO)
2. What shape is glucose in?
3. What elements are found in carbohydrates? Any specific ratios?
4. Glucose is a monomer for what macromolecule?
5. What is a disaccharide? Give examples.
6. What is a polysaccharide? Give examples.
7. Simple sugars like glucose are called ______.
8. What are 3 functions of carbohydrates for living organisms?
Macromolecule: Protein
Monomer: amino acid
Read page 170 in your text.
Construct an amino acid (glycine).
Place a BOX around the amino group on this picture.
Circle the carboxyl group on this picture.
9. Glycine is what type of monomer? (Two words)
10. What elements make up proteins? Are there any specific ratios?
11. Name the 4 things attached to the center carbon in ALL amino acids.
A. H______
B. C______G______
C. A______G______
D. V______G______
12. How many amino acids exist?
13. What element is found in amino acid that isn’t found in simple sugars like glucose or fructose?
14. Amino acids join together to make what type of macromolecule?
15. Give some examples of the different ways that proteins are structured.
16. What are some of the functions of proteins in the body? (List several)
Macromolecule: Lipid (fat)
Monomers: Glycerol + 3 Fatty Acids
Read page 169 in your text.
Construct a glycerol molecule.
Place a CIRCLE around a hydroxyl group.
17. Lipids are made up of what elements? Are there any specific ratios?
18. Glycerol is one of two molecules that make up lipids known as
_T______S_.
19. Besides glycerol, what 3 other molecules make up a triglyceride?
20. Give 3 functions of lipids.
Construct a Fatty acid molecule.
Place a BOX around the hydrocarbon chain in these pictures.
Circle the carboxyl group in both pictures.
21. Fatty acids are made of long chains of ______atoms with attached ______atoms.
22. How many bond(s) does each carbon atom have?
23. How many bond(s) does each hydrogen have?
24. How are the saturated and unsaturated fatty acids different?
25. Besides triglycerides, name two other types of lipids and describe their function.
A. P______:
B. S______:
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