Name:
Period:
Lab Exercise: Macromolecules
Lipids, Proteins, Carbohydrates, and Nucleic Acids
Date:
Objectives:
 Become familiar with structure and function of organic molecules found in living organisms.
 Understand how monomers join to make polymers. (Mono= one) (Poly= many) (Mer= part)
 Understand how polymers are broken down.
Instructions: This lab is an activity that will take place throughout several days. It will involve both
drawing, labeling and building models. You will need colored pencils!
Materials: Regular toothpicks (single covalent bonds)
Tooth picks split in half (double covalent bonds)
Gummi Bears in assorted colors- (different elements) see chart below
Colored pencils
Background info: Living cells are made up of mostly water. The rest of the cell is largely made up of
compounds that contain Carbon. Living things are made up of proteins, DNA, fats, and sugars. All of
these molecules are made of Carbon. Carbon containing compounds are called organic. Inorganic
compounds do not contain carbon. Therefore, living things are composed of organic compounds.
Molecules are 3-D in actuality we draw them and build them 2-D for simplicity.
During this lab activity, you will be exploring the structure of these compounds. This will involve making
sketches and models. There will also be several questions that you must answer on your answer sheet. For
your drawings (sketches) you will need colored pencils to indicate the elements involved:
ELEMENT
Carbon
Hydrogen
Oxygen
Nitrogen
SYMBOL
C
H
O
N
COLOR
Red
White/yellow
Orange
Green
Atoms join together to form molecules. These molecules are held together by bonds. In this lab you will
use toothpicks to represent the bonds. Important note: use regular toothpicks to represent a single
covalent bond, and a split toothpick to represent a double covalent bond. Remember, covalent bonds
are bonds in which electrons are shared.
KEY:
Single covalent bond
Double covalent bond
Common Functional Groups
PRE-LAB
Part I: Background
 How many valence electrons to the following atoms have?
1
Functional Group Structural formula
Hydroxyl
-O--H
Carboxyl
O
H-C-C-O--H
O
C-O--H
____ C
____H
____O
 How many bonds will each of the following atoms form?*
____ C
____H
____O
H-C-C-O--H
____N
Amino
2
Ex.
H
N
____N
H
H
N
H
C
H
C O--H
H
*this tells us how many lines should be connected to each of these atoms when we are looking at the
structural formula.
Part II: Proteins
Refer to the diagrams of the amino acids shown below: Alanine and Glycine.
H
H
H
C
C
C
H
H
H
ALANINE
GLYCINE
3
 Fill in the empty boxes with the correct atoms. These are major functional groups. See the chart
above to fill them in. Both amino acids should have an amino and carboxyl group.
4
 Write each element symbol using the color from the key on the front page.
5
 Count the number of carbon, hydrogen, oxygen, and nitrogen atoms in each molecule. Record
answers. Alanine C___________ H___________ O____________ N____________
Glycine C___________ H___________ O____________ N____________
6
 Count the number of single covalent bonds and double covalent bonds in each. Record answers.
Alanine Double bonds________ Single bonds___________
Glycine Double bonds________
Single bonds___________
7
 Find each amino group and draw a SQUARE around each. Label.
8
 Draw a CIRCLE around the carboxyl group in both. Label.
 Part II: Proteins (cont.)
 The 2 functional groups that you identified above are present in all 20 amino acids!
9
 Now look at alanine. Draw a broken line square (------) around the group of atoms that is different
in alanine.
10
 What is the group called that you drew a broken line square around called? ___________________
For this next section you will need to draw the molecule formed by the two amino acids from the previous
page. Take out the –OH from Alanine and –H from Glycine. The bond connecting the 2 amino acids is
called a peptide bond. Use the proper colors for the elements!!!
11
 What does the “di” refer to in this molecule_____________________________
DIPEPTIDE DIAGRAM
***When drawing the two amino acids, NH2, CH3,
or COOH should be drawn correctly. See the
functional group chart for details!
12
14
15
5
16
5
17
5
18
5
 Besides the dipeptide what other molecule is formed during this process? ___________
19
20
5
 Which would be best described as a polymer? Protein or amino acid? Why?
 What is the process called that bonds these 2 amino acids together? ____________
 Why is this a good name for this process?
 Draw and label the peptide bond with and arrow pointing to it.
Part III: Carbohydrates
 Shade in glucose and fructose in the boxes below. Remember to use the correct colors for each
of the atoms.
H
O
H
H
C
H
O
O
C
H
H
H
H
H
O
O
H
H
C
H
C
C
O
O
H
H
H
C
O
C
H
O
C
C
C
H
C
H
C
H
O
O
H
O
H
H
H
H
Glucose
Fructose
 Look at the glucose molecule. How many carbon atoms are there? Hydrogen? Oxygen?
21
5
22
5
23
5
24
5
25
5
26
5
27
28
5
 Record answers. C_____________
H______________
O_____________
 What is the ratio of carbon to hydrogen to oxygen. Reduce to lowest common denominator.
 _____________________________
 Now count the number of carbon atoms in fructose. Atoms of Hydrogen? Oxygen? Record.
C______________
H______________ O______________
 What is the ratio of C to H to O? ________________
 What do both monosaccharides have in common besides their ratio? _________________________
 Sucrose (table sugar) can be made by joining the glucose and fructose molecules together. Glucose
and fructose are both monosaccharides. What then, would be an appropriate name for sucrose since
you are combining 2 MONOsaccharides together? _________________________________
 Draw a box and label the hydroxyl group (-OH) on the far right of the glucose molecule and the
middle hydrogen (-H) on the left side of the fructose in the above diagrams. These two are
important in dehydration synthesis. hint hint.
 Draw a diagram below showing glucose and fructose combined to make sucrose. Use the correct
colors.
29
33
34
5
35
5
36
5
37
5
 What are the 2 molecules formed? ___________________________________________
 What is this process called? ________________________
 Is this process similar to joining amino acids to make a dipeptide? Explain why or why not.
 What atom is the ‘connecting’ element in the molecule you just drew? ___________
Part IV: Lipids
Lipids are compounds that are insoluble in water (don’t mix). Lipids are commonly called fats, oils, and
waxes. Similar to carbohydrates, lipids are made of carbon, hydrogen, and oxygen. All lipids have a
greater number of carbon-hydrogen bonds and less oxygen than carbohydrates. Due to the fact that they
have a greater number of C-H bonds, they are able to store more energy than carbohydrates. In fact, one
gram of fat stores 9 calories, and a gram of carbohydrate or protein is usually 4-5 calories.
38
5
39
5
40
5
Most lipids contain a glycerol molecule and 3 fatty acid molecules. Fatty acids are long chains of
hydrogen and carbon atoms that have a carboxyl group attached at one end.
 What are the types of lipids described above called (monomers of lipids)? ____________________
Lipids are important in many ways. They are important in forming biological membranes, some are
chemical messengers, and store energy!
 What are the lipids called that form the majority of the cell membrane? ______________
 Draw and label the lipid type for the above question. No need to worry about colors. I want the
basic structure not the structural formula like we have been doing. Check pg. 59 or your notes for
a picture of one.
 Draw a diagram of Glycerol and shade in the molecule of butyric acid. Remember to use the correct
colors.
41
45
Butyric Acid
46
5
Glycerol
 Draw a box around the carboxyl and hydroxyl groups and label them in each molecule above if they
are present.
Part IV: Lipids (cont.)
 Draw 3 butyric acid molecules bonded to the glycerol molecule. Again remember your colors.
47
52
53
 After you combined the 3 fatty acid molecules with the glycerol molecule, what compound did you
form? __________________________________
54
 What compound was formed by removing atoms? ____________________________
55
 What is this process called? ______________________________
56
 What is the exact opposite of the process mentioned above that breaks down all of the polymers
called?
Part V: Nucleic Acids
 Draw a nucleotide in the space below. Color the phosphate group purple, the pentose sugar red, and
the nitrogenous base green.
57
60
61
 What are the types of polymers formed by this monomer? ____________________
62
 What is the main function of those polymers? _______________
63
 What process do you think bonds these monomers together to form those polymers? (what process
have we witnessed so far?) ____________________________
64
 What molecule has a nucleotide plus 3 phosphate groups? _________________________
 What’s the role of this molecule? ____________________________
65
27 Points
GUMMI BEAR LAB
Procedure:
Name:
A. Obtain supplies from the teacher.
Period:
a. One bag of gummi bears
i. White/Yellow bears(Hydrogen)- 12
Date:
ii. Orange bears(Oxygen)- 6
iii. Red bears(Carbon)- 6
iv. Green bears(Nitrogen)- 3
b. Toothpicks
i. Regular(single bonds)- 20 (You can break in half) Use two for double bonds
B. Build the 2 separate amino acids alanine and glycine that you shaded in during the pre-lab. Use
the same color gummi bears as you did when you colored in the atoms.
1
C. Could you describe both of these amino acids as “organic”? Why or why not?
________________________________________________________________
D. Now using the two amino acids you just built and using the dipeptide diagram you drew make
that dipeptide with the gummi bears. Yes you will need to remove some atoms and rearrange
your molecules. Remember to use correct type of toothpick and rules of bonding.
2
E. What is left over?_______________
3
Raise your hand to notify me you’re done to explain what you did. Teacher approval?
______________
4
F. What is the process called that you just modeled out with the gummi bears?________________
5
G. What is the process that breaks this molecule down called (reverse of it)? _______________
H. Take apart the molecules.
I. Build the 2 separate sugar molecules you drew in your pre-lab.
J. Build the disaccharide you drew in the pre-lab using those 2 molecules.
6
7
K. What is left over? _______________
Raise your hand to notify me you’re done to explain what you did. Teacher approval?
______________
L. Take apart the molecules.
a. Throw away broken toothpicks.
b. Put the regular toothpicks in appropriate containers.
c. Put your names on a half sheet of paper and put them in the bag with the gummi bears.
d. Clean desk top with a wet paper towel.
e. Check floor for fallen items and pick them up and put them in the proper place.
M. Build one glycerol molecule and three butyric acid molecules. Like the ones you drew and
shaded in on the pre-lab.
N. Now looking at the lipid molecule you drew with these 4 parts create that molecule with the
gummi bear molecules.
8
9
O. What is left over? _______________
Raise your hand to notify me you’re done to explain what you did. Teacher approval?
______________
P. Take apart the molecules.
a. Throw away broken toothpicks.
b. Put the regular toothpicks in appropriate containers.
c. Put your names on a half sheet of paper and put them in the bag with the gummi bears.
d. Clean desk top with a wet paper towel.
e. Check floor for fallen items and pick them up and put them in the proper place.
Q. You and your partner may now eat your gummis (if you want to)
10
R. Did you have fun? (Circle one)
Yes!
Sort of…
Not really…
No Way!
S. Start work on wrap-up questions.
GUMMI BEAR LAB WRAP-UP
1. What is a monomer? What is a polymer?
2. What are the monomers for the following macromolecules?
a. Carbohydrates-______________________________
b. Protein-____________________________________
c. Nucleotides-________________________________
d. Lipids-(there is 2)____________________________(these are key parts not monomers)
3. What is the molecular formula for each of the following function groups? Then draw the
structural formula below it.
a. Hydroxyl Group:_______ b. Carboxyl Group:__________ c. Amine Group:_______
4. How many valence electrons does each of the following atoms have?
a. Carbon:____
b. Oxygen:____
c. Hydrogen:____
d. Nitrogen:_____
5. How many bonds does each of the following atoms form?
a. Carbon:____
b. Oxygen:____
c. Hydrogen:____
d. Nitrogen:_____
6. What is a dipeptide molecule?
7. What is a disaccharide?
8. What is the molecule called when 3 or monosaccharides are bonded together?
9. What is the molecule called (2 names) when 3 or amino acids are bonded together?
10. What is the major difference between inorganic and organic molecules?
11. What are the major parts of an amino acid?
a. ___________________
b. ___________________
c. ___________________
12. How many different amino acids are there?________
13. What process do all four macromolecule monomers go through to build their polymers?
14. What process do all four macromolecule monomers go through to break down their polymers?
15. What are the 3 major parts of a nucleotide?
16. What are the functions of each of the macromolecules.
a. Carbohydrates:___________________________________________________________
b. Proteins:________________________________________________________________
c. Lipids:_________________________________________________________________
d. Nucleic Acids:___________________________________________________________