1. The Structure and Function of Macromolecules
CHAPTER 5
The Structure and Function
of Macromolecules
What
Macromolecules
Can you see in
This picture?

2. What makes you- you… or any organism on Earth what it is
What makes you- you… or any organism on Earth what it is? What four types of molecules are cells and organisms composed of?

3. Water, minerals, vitamins
Carbohydrates
Protein
Lipids

4. Big Idea 1: The process of evolution drives the diversity and unity of life.
The origin of living systems is explained by natural processes. Molecular and genetic evidence from extant and extinct organisms indicates that all organisms on Earth share a common ancestral origin of life.
1. Scientific evidence includes molecular building blocks that are common to all life forms: glucose, amino acids, nucleotides, fatty acids + glycerol, ATP> ADP
Scientific evidence includes a common genetic code: DNA  RNA  Protein
PROTEIN
Nucleic Acids
Lipids
Carbo-hydrates

5. Autotrophs- photosynthesis Heterotrophs- consume others
Carbon dioxide from atmosphere
Water from soil
Phosphorus
Nitrogen
In water
Sulfur
Heterotrophs- consume others
Carbohydrates
Protein
Lipids
Nucleic Acids
Photons + 6CO2 + 6H20 --> C6H12O6 + 6O2
C6H12O > 6 CO2 + 6 H ATP

6. POLYMERS (macromolecules) & MONOMERS (building blocks)
PROTEINS
Amino Acids
(20 kinds)
NUCLEIC ACIDS
Nucleotides
(4 kinds= A,T,G,C)
CARB
OHYDRATES
Many… (glucose)
Monosaccharides
LIPIDS*
(not a true macromolecule)
Glycerol
Fatty Acids
(many)

7. POLYMER =
A long molecule made of identical monomers linked together with covalent bonds.
Ex.
DNA, RNA, Protein, Polysaccharides

8. THE CONDENSATION REACTION
aka DEHYDRATION SYNTHESIS

9. condensation rxn dehydration synthesis rxn
A way to connect monomers together to build a larger molecule… polymer
H is taken off of one monomer
OH is taken off a second monomer &
the monomers form a covalent bond.
Water is produced.
Covalent bond is formed between monomers.

10. HOW WOULD YOU DO THE OPPOSITE REACTION???
What is it called?

11. Figure 5.2 The synthesis and breakdown of polymers
THE HYDROLYSIS REACTION
dissociation

12. The hydrolysis rxn = Hydro “water” + Lysis “to cut”
Breaking C-C bonds within a polymer using water.
Split a water & add H and OH back to the monomers.

13. Big Idea 4: Biological systems interact, and these systems and their interactions possess complex properties.
Interactions within biological systems lead to complex properties.
Structure and function of polymers are derived from the way their monomers are assembled.
Carbohydrates are composed of sugar monomers whose structures and bonding with each other by dehydration synthesis determine the properties and functions of the molecules.
Ex. cellulose versus starch.
✘ The molecular structure of specific carbohydrate polymers is beyond the scope of the course and the AP Exam.

14. CARBOHYDRATES Contain the elements: C, H, O
Molecular ratio of elements: 1:2:1

15. MONOSACCHARIDES = simple sugars
PROPERTIES:
Hydrocarbon chains with hydroxyl groups
Polar molecules
General formula = (CH2O)n (n=3-7)
Role = fuel for cellular work (cellular respiration)
Serves as the carbon skeleton for other types of monomers (ex. Amino acids)
Component of nucleotides (ribose/deoxyribose)

16. THE 3 MOST IMPORTANT:
Hexose sugars: C6H12O6
Glucose-
straight chain ALDEHYDE
2. Galactose-
3. Fructose-
Straight chain KETONE

17. Question:
These were branched diagrams… but when dissolved in water all three take on what form?

18. Answer: Ring

19. Q: how are these forms different???
A: Oxygen is in the “ring”… functional grps.
Notice the bond is between the carbonyl on
carbon 1 and the hydroxyl on carbon 5.

20. what is the importance of glucose?
ATP
Main fuel source to generate energy (ATP) via cell respiration in the mitochondria
ADP

21. 2. DISACCHARIDES- double sugar
Comprised of: 2 monosaccharides
Bonded together via: a condensation rxn
glycosidic linkage

22. 2. DISACCHARIDES- double sugar
Types:
a) Sucrose =
glucose + fructose
b) Maltose =
glucose + glucose
c) Lactose =
glucose + galactose
Illustrative examples.
SUCROSE

23. Figure 5.5x Glucose monomer and disaccharides
Sucrose
Maltose

24. 3. POLYSACCHARIDES- complex carbohydrates
Polymerization
STARCHES =
glucose monomers bound repeatedly;
Short term energy storage for plants inside plastids (ex. amyloplast)
1) Amylose (unbranched)
2) Amylopectin (branched)

25. b) GLYCOGEN = highly branched & coiled glucose monomer chains
Short term energy storage for animals inside liver and muscle cells.

26. c) CELLULOSE = Chains of beta glucose monomers
Every other glucose is upside down in the polymer
Straight chain (fibers), never branched
Cell walls of plants- structure only.

27. Figure 5.7x Starch and cellulose molecular models
 Glucose
 Glucose
Cellulose
Starch

28. Why do animals have difficulty digesting cellulose?
Animals lack the necessary enzyme to break the Beta linkages
Cows overcame this problem by harboring bacteria that can break down cellulose.

29. Figure 5.x1 Cellulose digestion: termite and Trichonympha
Termites can do it to because of a symbiotic relationship
with this kind of protazoan…. Trichonympha.

30. d) CHITIN Similar to cellulose (also contains N)
Used in cell walls of fungi and in the exoskeletons of arthropods like:
- insects
- spiders
- scorpions
- lobsters, shrimp

31. “chitin is excitin’! “

32. LIPIDS Contain the elements:C, H, O Properites:
Little or no affinity for water (hydrophobic)
Consist mostly of hydrocarbons and some polar bonds with oxygen.
Smaller than true macromolecules
(nucleic acids, proteins, carbohydrates)

33. 1. Fats and Oils One molecule of fat is made of: - glycerol
- fatty acids
Triglyceride =
- three fatty acids
- one glycerol

34. long hydro-carbon
chains are why fats
are hydrophobic!
nonpolar
GLYCEROL STRUCTURE
Alcohol
3 carbon’s
each w/ hydroxyl grp.
FATTY ACID STRUCTURE
Acid
Long carbon skeleton
(16-18 C’s long)
carboxyl grp. at one end

35. Figure 5.11 Examples of saturated and unsaturated fats and fatty acids
No double bonds between carbon atoms.
Hydrogen bonded as much as possible onto the carbon skeleton.
“Saturated with hydrogens” = SATURATED FAT

36. Figure 5.11 Examples of saturated and unsaturated fats and fatty acids
Double bonds exist between carbon atoms.
Formed by the
removal of hydrogen from the carbon skeleton.
“Not saturated with hydrogens” =
UNSATURATED FAT

37. WHICH IS HEALTHIER TO COOK WITH/ EAT???
Saturated Fats
BAD
Solid at room temp
Animal fats
Unsaturated Fats
GOOD
Liquid at room temp
Plant & Fish fats

38. Diets rich in saturated fats contribute to Atherosclerosis-
Cardiovascular disease
Plaques develop inside blood vessels blocking flow and making them inelastic.
heart attack, stroke,thrombosis

39. why are fats perfect for storage and energy?
They are LIGHT! Which is important for animals & seeds.
1 gram of fat stores more than twice as much energy as a gram of polysaccharide.

40. 2. PHOSPHOLIPIDS The main component of cell membranes.
Are comprised of :
a) two fatty acids
b) glycerol
c) phosphate group (negative)
& various attachments
glycerol/phosphate is the “HEAD”
two fatty acids are the “TAILS”

41. Phospholipid’s Key property:
Ambivalent towards water.
When placed in water they self assemble into clusters that shield the hydrophobic tails from the water.
- micelle
- phospholipid bilayer
- coacervates

42. 3. STEROIDS Basic structure: four fused rings.
Vary in the functional groups attached to the rings.

43. EXAMPLES: A. CHOLESTEROL 1) Component of animal cell membranes.
2) Precursor to other steroids
sex hormones:
B. ESTROGEN
C. PROGESTERONE
D. TESTOSTERONE
stress hormone:
E. Cortisol
F. ANABOLIC steroids-
Ex. TESTOSTERONE
promotes muscle growth and development

44. End. (part 1)

45. PROTEINS Contain the elements: C,H,N,O
The building blocks are: AMINO ACIDS.
Account for > 50% of the dry weight of most cells.
Proteios, “first place”
Fun fact:You should eat 9 grams of protein for every 20 pounds of body weight.

46. Protein functions: Structural support Storage Transport of substances
Keratin, collagen, cytoskeleton of cells
Storage
ex. albumin of egg whites store amino acids
Transport of substances
Membrane tunnels
Signaling
Hormones like insulin, oxytocin, glucagon
Movement
Contractile proteins like actin and
DEFENSE
Ex. Antibodies
SARCOMERE functional unit
of a muscle cell… made of
Actin and Myosin proteins

47. ENZYMES
Biological molecules that catalyze (increase the rates of) chemical reactions.
The set of enzymes made in a cell determines the metabolic pathways that will occur there.

48. AMINO ACID STRUCTURE asymmetric carbon Amino group Carboxyl group
Hydrogen atom
R group (variable)
- side chain
- 20 different ones
- Polar, nonpolar,
acidic, or basic

49. 1.Proteins are POLYPEPTIDES
The peptide bond: Covalent bond between
the carboxyl group of one amino acid and
the amino group of another
Formed by a condensation rxn.

50. Proteins have an amino (NH2) end and a carboxyl (COOH) end, and consist of a linear sequence of amino acids connected by the formation of peptide bonds by dehydration synthesis between the amino and carboxyl groups of adjacent monomers.

51. 2. SHAPES OF PROTEINS
The specific order of amino acids in a polypeptide (primary structure) interacts with the environment to determine the overall shape of the protein, which also involves secondary tertiary and quaternary structure and, thus, its function.
The four levels of protein structure.

52. 2. SHAPES OF PROTEINS
PRIMARY STRUCTURE- unique sequence of amino acids (like the order of letters in a very long word)
SECONDARY STRUCTURE- coiled and folded patterns due to hydrogen bonds. Occurs between atoms attached to the backbone- but not R group.
1) a-helix- coil held by hydrogen bonding between every 4th amino acid.
Ex) keratin
2) B-pleated sheet- cross-linkage between two or more regions that lie parallel to each other.
Ex) silk

54. C. TERTIARY STRUCTURE
irregular contortions from interactions between R-groups (side chains)
1) hydrophobic/ van der waals interactions (nonpolar R-groups)
2) hydrogen bonding
(polar R-groups)
3) disulfide bridge (s-s, from -SH R-groups)
4) ionic bonding (+ & -)

55. TERTIARY STRUCTURE
The R group of an amino acid can be categorized by chemical properties:
hydrophobic
hydrophilic and
ionic.
and the interactions of these R groups determine structure and function of that region of the protein.

56. D. QUATERNARY STRUCTURE
1) Triple Helix- three alpha helixes
ex. Collagen… rope-like
2) Globular- two or more polypeptide chains
ex. Hemoglobin… a & B chains

58. Figure 5.24 Review: the four levels of protein structure

59. What happens when a protein becomes denatured?
It loses its native conformation.
Is thus… biologically inactive.
ENVIRONMENT: pH, salt concentration, high temperature, can unravel the protein.
Yes, proteins can become “renatured”.

60. Table 5.2 Polypeptide Sequence as Evidence for Evolutionary Relationships

61. NUCLEIC ACIDS: DNA & RNA (S&F)
DNA molecule is comprised of a series of nucleotides that can be linked together in various sequences; the resulting polymer carries hereditary material for the cell, including information that controls cellular activities.

62. Q: What is a double helix?
A: two polynucleotides that spiral around an imaginary axis. Double stranded.
Q: What holds the double helix together?
A: hydrogen bonds between nitrogenous bases hold the 2 strands together.
Q: What are base pairs?
A: bases that are compatible w/ e/o… that hydrogen bond to eachother.
1) Adenine - Thymine (2 H bonds)
2) Guanine - Cytosine (3 H bonds)

63. James Watson and Francis Crick
Rosalind Franklin

64. DNA
Unit of heredity. Enables living things to reproduce their components from generation to generation.
Directs protein synthesis.
NUCLEOTIDE is the chemical building block
5 carbon sugar: deoxyribose
Phosphate group
Nitrogen bases
1. Adenine, Guanine
(purines: 2 rings)
2. Cytosine, Thymine
(pyrimidines: 1 ring)

65. Figure 5.29 The components of nucleic acids

66. Figure 5.30 The DNA double helix and its replication
DNA is self-replicating
Complementary base
pairing makes the precise
copying of DNA possible.

67. 2. RNA * Molecules that function in the synthesis of proteins!
5 carbon sugar: RIBOSE
Phosphate group
Nitrogenous bases
1. Adenine, Guanine
2. Cytosine, URACIL
* RNA is a single stranded molecule!

69. W/ your Partner Compare and contrast DNA with RNA in terms of: 1) Structure 2) Function 3) Evolutionary Relationships

70. THE END