Macromolecules

1. Unit 2: Macromolecules & Enzymes
Textbook Source: Chapter 6 Section 2 and 4
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2. LEARNING OBJECTIVES FOR UNIT 2
• To describe the basic molecular structure AND functions of
carbohydrates, lipids, proteins, and nucleic acids.
• To explain how enzymes speed up the rate of a
biochemical reaction by lowering the activation energy.
• To describe the effect of environmental factors (pH and
temperature) on enzyme activity.
2

3. Organic Compounds
• Are compounds that contain CARBON
• Macromolecules are LARGE organic
molecules (aka polymers)
3

4. FUNCTIONAL GROUPS
Functional groups are collections of atoms
in a molecule that participate in
characteristic chemical reactions.
You will notice them in the structures of
the four main macromolecules that we will
study in this unit.
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5. Macromolecules
• Four essential macromolecules are:
1.Carbohydrates
2.Lipids
3.Proteins
4.Nucleic acids
• Made up of smaller “building blocks” called
MONOMERS.
5

6. Dehydration Synthesis:
• Process that links monomers into polymers.
• Hydrolysis is the opposite process.
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7. The Four Essential
Macromolecules for Life
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8. 1. Carbohydrates
Components: C, H, O
Monomer = Monosaccharide (1 sugar unit)
Function:
• Mainly used for energy!
• Make plant cell wall (ex.cellulose)
Structure: ring formation
Ex: glucose (C6H12O6)
glucose 8

9. Types of Carbohydrates

11. Different types of Carbs.
• Simple sugars: provide energy but some lack
vitamins, minerals & fiber (ex. candy)
a) Monosaccharides
Ex. Glucose (corn sugar)
Ex. Fructose (fruit sugar)
b) Disaccharide
Ex. saccharose (cane sugar)
Ex. Lactose (milk sugar)
• Complex sugars: provides vitamins minerals, & fiber
a) Polysaccharides in plants: starch & cellulose
b) Polysaccharides in animals: glycogen
11

12. 12

13. Examples of Polysaccharides
13

14. 2. Lipids
Components: C, H, O
Functions:
• Energy storage
• Insulation
• Make up cell membranes
Ex: Fats, oils, steroids, hormones,
phospholipids
Structure: long carbon chains or many
rings linked together (ex. steroids) 14

15. Components of a lipid:
1 glycerol and 3 fatty acids.
15
Teacher’s Notes:
•Hydrophobic
molecule (“water
fearing”)
•Will NOT dissolve in
water
•Nonpolar

16. TYPES OF STEROIDS:
1) HORMONES 2) CHOLESTEROL
16
Teacher’s Notes:
Steroid hormones help control metabolism, inflammation, immune functions, salt and
water balance, development of sexual characteristics, and the ability to withstand illness
and injury. The term steroid describes both hormones produced by the body and
artificially produced medications that duplicate the action for the naturally occurring
steroids.

17. ANABOLIC STEROIDS:
Teacher’s Notes:
• Anabolic steroids are available
legally only by prescription, to treat
conditions that occur when the
body produces abnormally low
amounts of testosterone, such as
delayed puberty and some types of
impotence. They are also
prescribed to treat body wasting in
patients with AIDS and other
diseases that result in loss of lean
muscle mass.
• Anabolic steroids are being
abused by some athletes and
others to enhance performance or
improve physical appearance.
17

18. Structure of a Phospholipid
18

19. Structure of Phospholipid
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20. 3. Proteins (Polypeptides)
• Components: C, H, O, N
• Monomer = Amino acids
• Structure: always has a NH2 , and COOH group
• Amino acids peptide chains  proteins
• Are assembled in the ribosome of the cell.
20
Teacher’s Note:
Ribosomes are the cell’s protein factories.

21. Functions of Proteins
• Make up structures (ex. fur, nails, muscles)
• Defend against foreign substances (ex. Antibodies)
• Transport (ex. Hemoglobin)
• Cellular signaling (ex. Hormones)
• Make up ENZYMES
21

22. Structure of an Amino Acid
22
amino
There are 20 amino acids with a different R replaceable group
giving each one very unique chemical properties

23. Examples of Amino Acids
23

24. Levels of Protein Structure
24

25. ENZYMES:
• Speed up the rate of chemical reactions by
weakening bonds thus lowering the activation
energy to start a reaction.
• Activation energy: It’s the required energy for
a reaction to occur.
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26. Lowering the Activation Energy
Teacher’s Notes: When enzymes are present, the cell spends less energy to start a
chemical reaction.
26

27. Example of a Chemical Reaction in the presence of
an Enzyme
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28. How do enzymes work?
28

29. Enzyme-Substrate Complex:
A substrate (a reactant):
• fits into the active site like a key in a lock
(known as the “Lock & Key Model”)
• It is specific to an enzyme
29
Substrate Enzyme Joins
Teacher’s notes: Thousands of different
enzymes exist in the body.

30. Enzymes:
• Can be re-used
• Can reach saturation.
30
Teacher’s Notes:
Saturation means that
all of the enzyme
molecules are occupied
with substrate. Adding
more substrate will not
increase the rate of
reaction because
the enzymes are
already working at full
capacity.
If an enzyme is
unsaturated (not all
molecules are busy
with substrate), than
adding more substrate
will increase the
reaction rate, because
more enzyme
molecules can be
working.

31. INHIBITORS:
31

32. What can destroy an enzyme?
Changes in:
• pH
• Salt concentration
• Temperature
Once denatured (destroyed) it can’t
function properly.
32

33. Denaturing a Protein
Teacher’s Notes: Cooking an egg is an example of 33
denaturing a protein (notice the change in the egg
whites)

34. 4. Nucleic acids
Components: C, H, O, N, P
Two types: DNA, RNA
Monomer = nucleotide
Function:
• Holds & transfer information
• Codes for proteins.
Structure: single or double stranded
34

35. DNA is made of many “nucleotides”
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36. Macromolecules
36

37. Macromolecules
37

38. Activity: Identifying Macromolecules Activity
Part A:
Identify the macromolecules labeled A-I
Part B:
Look at the data table with the information on Samples 1 -5
1)Which samples are macromolecules?
2) What type of macromolecules are they?
Part C:
Answer Q1-15 in your notebooks
38

39. Part A: Classify the following
macromolecules.
A.
B.
C.
D.
E. F.
G.
Tip: R means “replaced”. It is not an element.

40. Part A: Classify the following
macromolecules (CONT.)
H.
I.
Hint: You should get (3) carbs, (1)
protein, (3) lipids and (2) nucleic acids

41. Part B:
Look at the data table 2. Identify the samples that have macromolecules
AND to what category they belong to (carbs, proteins, lipids, or nucleic
acids)
Data Table 2
Samples
1 2 3 4 5
Ar 
N    
Ne
O    
Cl 
H   
C   
P 
Hint: In order to be a
macromolecule it has
to have one of these
combinations:
• C,HO
or
• C,H,O,N
or
• C,H,O,N,P