1. Macromolecules: Ch. 5 Part 1
AP Biology

2. Macromolecules
Macromolecules (MMs)- The terms “structure” and “function” are inseparable when talking about these molecules.

3. Macromolecules The four that we will be talking about:
Carbohydrates (Notes PART 1)
Lipids (Notes PART 1)
3. Proteins (Notes PART 2)
4. Nucleic Acids (Notes PART 2)

4. Macromolecules
Carbs, proteins, nucleic acids are polymers (poly = many) built from monomers (mono = one). Joined covalently.
Monomers are joined together by condensation reactions (specifically a dehydration rxn- a loss of one water molecule). Requires energy.
Polymers are broken into monomers by hydrolysis (water is “added”)- the reverse of a dehydration rxn

5. Building and Breaking

6. Dehydration Synthesis and Hydrolysis
Animation

7. Analogy of macromolecules Monomer – 1 building block of the polymer (macromolecule) Polymer – built from monomers using dehydration synthesis Polymers: Carbohydrates Proteins Nucleic acids *Lipids – consider an exception; but usually built from smaller pieces

8. 1) CARBOHYDRATES

9. Carbohydrates

10. Carbohydrates

11. Aldose (Aldehyde Sugar) Ketose (Ketone Sugar)
Figure 5.3c
Aldose (Aldehyde Sugar)
Ketose (Ketone Sugar)
Hexoses: 6-carbon sugars (C6H12O6)
Figure 5.3 The structure and classification of some monosaccharides.
Glucose
Galactose
Fructose

12. Monosaccharides Glucose (C6H12O6)- is the most common Mono
Although these sugars can be in a linear form, they commonly form rings.
These sugars can be used individually for energy or can be incorporated into a di/polysaccharide
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13. (a) Linear and ring forms
Figure 5.4 1 6 6 2 5 5 3 4 1 4 1 4 2 2 5 3 3 6
(a) Linear and ring forms 6
Figure 5.4 Linear and ring forms of glucose. 5 4 1 3 2
(b) Abbreviated ring structure

14. Disaccharides

15. (a) Dehydration reaction in the synthesis of maltose
Figure 5.5
1–4 glycosidic linkage 1 4
Alpha Glucose
Alpha Glucose
Maltose
(a) Dehydration reaction in the synthesis of maltose
1–2 glycosidic linkage 1 2
Figure 5.5 Examples of disaccharide synthesis.
Alpha Glucose
Beta Fructose
Sucrose
(b) Dehydration reaction in the synthesis of sucrose

16. c. Polysaccharides “Polys”

17. Storage Polysaccharides: PLANTS

18. Straight line, but coils
Figure 5.6
Chloroplast
Starch granules
Amylopectin
Straight line, but coils
Amylose
(a) Starch: a plant polysaccharide
1 m
Mitochondria
Glycogen granules
Figure 5.6 Storage polysaccharides of plants and animals.
Glycogen
(b) Glycogen: an animal polysaccharide
0.5 m

19. Storage Polysaccharides: ANIMALS
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20. (a) Starch: a plant polysaccharide
Figure 5.6
Chloroplast
Starch granules
Amylopectin
Amylose
(a) Starch: a plant polysaccharide
1 m
Mitochondria
Glycogen granules
Figure 5.6 Storage polysaccharides of plants and animals.
Glycogen
(b) Glycogen: an animal polysaccharide
0.5 m

21. Structural Polysaccharides: PLANTS

22. C1 = the carbon to the right of the O
Figure 5.7
C1 = the carbon to the right of the O
(a)  and  glucose ring structures 4 1 4 1
 Glucose
 Glucose 1 4 1 4
Figure 5.7 Starch and cellulose structures.
(b) Starch: 1–4 linkage of  glucose monomers
(c) Cellulose: 1–4 linkage of  glucose monomers
= OH BELOW the ring on C1; same side
 = OH ABOVE the O; alternation of sides

23. Cellulose

24. Cellulose microfibrils in a plant cell wall
Figure 5.8
Cellulose microfibrils in a plant cell wall
Starch and Cellulose Animation
Cell wall
Microfibril
10 m
0.5 m
Figure 5.8 The arrangement of cellulose in plant cell walls.
Cellulose molecules
 Glucose monomer

25. Hydrolysis of Cellulose
NOT EASY for animals to break bonds of cellulose!
Enzymes that digest starch by hydrolyzing  linkages; can’t hydrolyze  linkages in cellulose!
Cellulose in human food passes through the digestive tract as insoluble fiber.
*Many herbivores, from cows to termites, have symbiotic relationships with these microbes to help break down the bonds in plant cell walls.

26. Structural Polysaccharides: ANIMALS

28. © 2011 Pearson Education, Inc.

29. Figure 5.9 Chitin, a structural polysaccharide.
*Chitin is used to make a strong and flexible surgical thread that decomposes after the wound or incision heals.

30. Review of Glycosidic Linkages
and Shape
Polymers with  glucose are helical
Starch (amylose/amylopectin)
Glycogen
Polymers with  glucose are straight
Cellulose- parallel strands of long cellulose molecules group into microfibrils (strong building structure for plants)
Chitin
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31. Which polysaccharide has the greatest number of branches?
cellulose
starch
amylose
glycogen
Answer: d
Concept 5.2 31

32. Which polysaccharide has the greatest number of branches?
cellulose
starch
amylose
glycogen
Answer: d
Concept 5.2 32

33. If actively growing cells are fed 14C-labeled glucose, what macromolecules will become radioactive first?
proteins
starch
nucleic acids
fatty acids
Answer: b
This question relates to Concept 5.2. 33

34. If actively growing cells are fed 14C-labeled glucose, what macromolecules will become radioactive first?
proteins
starch
nucleic acids
fatty acids
Answer: b
This question relates to Concept 5.2. 34

35. Why are human enzymes that digest starch unable to digest cellulose?
Cellulose is made of amino-containing sugars that cannot be metabolized.
Cellulose is only in plants, therefore humans do not have enzymes to break plant polysaccharides.
Cellulose has beta-glycosidic linkages; starch-digesting enzymes break only alpha-glycosidic linkages.
Cellulose has alpha-glycosidic linkages that only bacterial enzymes can break.
Answer: c
Concept 5.2 35

36. Why are human enzymes that digest starch unable to digest cellulose?
Cellulose is made of amino-containing sugars that cannot be metabolized.
Cellulose is only in plants, therefore humans do not have enzymes to break plant polysaccharides.
Cellulose has beta-glycosidic linkages; starch-digesting enzymes break only alpha-glycosidic linkages.
Cellulose has alpha-glycosidic linkages that only bacterial enzymes can break.
Answer: c
Concept 5.2 36

37. LIPIDS Functions- The most biologically important lipids are:
Fats (Triglycerides)- long term energy storage; cushioning; insulation
Phospholipids – cell membranes
Steroids – hormones; cholesterol in cell membranes

38. Lipids

39. Lipids
Fats- Assembled by dehydration reactions. Contains a glycerol molecule with a fatty acid(s) attached as a chain.

40. Figure 4.6 The role of hydrocarbons in fats. 10 m
Nucleus
Fat droplets
Figure 4.6 The role of hydrocarbons in fats.
10 m
(a) Part of a human adipose cell
(b) A fat molecule

41. Lipids

42. Lipids

43. Fatty acid (in this case, palmitic acid)
Figure 5.10
Fatty acid (in this case, palmitic acid)
Glycerol
(a) One of three dehydration reactions in the synthesis of a fat
Ester linkage – cov. bond in fats holding glycerol head to tails
Figure 5.10 The synthesis and structure of a fat, or triacylglycerol.
(b) Fat molecule (triacylglycerol)
Fats (TRIGLYCERIDES)- 1 glycerol head and 3 fatty acids tails

44. Lipids

45. 2 types of fats

46. 2 types of fats
*Double bonds= kink/bend in a hydrocarbon chain; liquids at room temp (can’t pack together tightly)
-olive, vegetable, fish oils

47. Lipids

48. Figure 5.11
(b) Unsaturated fat
(a) Saturated fat
Structural formula of a saturated fat molecule
Structural formula of an unsaturated fat molecule
Space-filling model of stearic acid, a saturated fatty acid
Space-filling model of oleic acid, an unsaturated fatty acid
Figure 5.11 Saturated and unsaturated fats and fatty acids.
A diet rich in saturated fats may contribute to cardiovascular disease through plaque deposits
Hydrogenation is the process of converting unsaturated fats to saturated fats by adding hydrogen
Cis double bond causes bending.

49. Phospholipids
Same as the fats above, but instead of 3 fatty acid chains attached to the glycerol, there are only 2.
Phosphate group is what takes the place of the missing fatty acid chain. “Phospho-lipid”
*The two fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head

50. Figure 5.12 The structure of a phospholipid.
Choline
Hydrophilic head
Phosphate
Glycerol
Fatty acids
Hydrophobic tails
Hydrophilic head
Figure 5.12 The structure of a phospholipid.
Hydrophobic tails
(a) Structural formula
(b) Space-filling model
(c) Phospholipid symbol

51. Phospholipids are the component of all cell membranes
Figure 5.13
Fluid mosaic model
Hydrophilic head
WATER
Figure 5.13 Bilayer structure formed by self-assembly of phospholipids in an aqueous environment.
Hydrophobic tail
WATER
Phospholipids are the component of all cell membranes

52. Lipids
Estradiol
Testosterone

53. Review Identify the functional groups in this structure.
What macromolecule is it?

54. (SUBUNITS) Monomer and Basic Structural Diagrams
Class:
Elements Involved:
Example:
Functions:
(SUBUNITS) Monomer and Basic Structural Diagrams
Carbo-
hydrate
C,H,O
1:2:1
GLUCOSE
C6H12O6
Mono-
Fructose
Glucose
Galactose
Di-
Lactose
Sucrose
Poly-
Starch
Glycogen
Cellulose
1.Stores Short Term Energy
- Animals ONLY=
- Plants ONLY=
2. Structural
support within cells: -
MONOSACCHARIDE =
Mono + mono =
Mono + mono +
+mono (X 100) =
Lipids
Mostly
C, H
Very
little O
Stores LONG TERM Energy
2. Form cell
membranes
3. Waterproof coverings
4. Chemical messengers
5. Insulation
6.Protection/cushioning
1 glycerol
3 fatty acids
Saturated-
Unsaturated-
SINGLE SUGAR
GLYCOGEN
STARCH
DISACCHARIDES
CHITIN (“KITE-IN”)
(INSECT EXOSKELETON;
Fungi cell walls)
PLANT CELL WALLS (CELLULOSE)
POLYSACCHARIDE
FATS
OILS
WAXES
STEROIDS
Testosterone
Estrogen
Cholesterol
NO DOUBLE BONDS IN FATTY ACID (SINGLE bonds=Straight lines = solids)
Saturated fat!
@ LEAST 1 DOUBLE BOND (double = kink in the leg; can’t fit closely= liquids)

55. * Phosphorus = phospholipid (2 tails)
Section 2-3
Concept Summary
Carbon
Compounds
include
Carbohydrates
Lipids
Nucleic acids
Proteins
that consist of
that consist of
that consist of
that consist of
Monosaccharides
Fatty acids
& Glycerol
Nucleotides
Amino Acids
which contain
which contain
which contain
which contain
Carbon,
hydrogen,
oxygen
Oxygen *
Carbon,hydrogen,
oxygen, nitrogen,
phosphorus
hydrogen,oxygen,
Nitrogen *
* Phosphorus = phospholipid (2 tails)
* Sulfur
Types of Bonds:
Covalent (Alpha or beta glycosidic)
Hydrogen (b/w
Types of Bonds:
- Covalent and hydrogen
- Ester linkages b/w hydrocarbon FA chain tails and glycerol head
Types of Bonds:
- Covalent (b/w sugar/ phosphates and sugar/bases)
- Hydrogen (b/w base pairs)
Types of Bonds:
PEPTIDE (b/w a.a.) PRIMARY
Hydrogen (b/w R groups of a.a) – SECONDARY
- disulfide bridges/ionic/ H bonds, hydrophobic interactions (b/w R groups of a.a) _TERT
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56. End of Part 1 notes!
See Macromolecules Part 2 note for Proteins, Nucleic Acids and practice questions.