8. What does it mean to be a
MACROmolecule?
You must be a Large molecule
You have a complex structure
Macromolecule
“little” molecule
9. I. Most macromolecules are polymers,
built from monomers
What is a polymer?
• Poly = many; mer = part.
• A long molecule made of monomers bonded
together
What is a monomer?
• A monomer is a sub-unit of a polymer.
10. Three of the classes of life’s organic molecules are
polymers
• Carbohydrates, Proteins, Nucleic acids
11. A. Making and Breaking Polymers
How do monomers bind to form polymers?
• condensation reactions called dehydration
synthesis (removal of water)
12. How can polymers break down when
monomers are needed?
Hydrolysis reaction
• Hydro = water; lysis = break
• Water is added and the lysis of the polymer
occurs.
16. What are Carbohydrates?
• Sugars and their polymers
• Carbo = carbon, hydrate = water; carbohydrates
have the molecular formula (CH2O)n
Functions of Carbohydrates in living things:
• Major fuel/energy source
• Can be used as raw materials for other
Macromolecules
• Complex sugars = building material in plants
What is the Carbohydrate Monomer?
• Monosaccharide (“mono” = one; “saccharide” =
sugar)
17. 1. Structure of Monosaccharides
Contain only C, H, O
Hydroxyl group is attached to each carbon
One carbon contains a carbonyl group
18. • Classified according to the size of their carbon chains and
location of Carbonyl group
19. In aqueous solutions many monosaccharides form
rings:
20. 2. Structure of Disaccharides
Consist of two monosaccharides
Are joined by a glycosidic linkage
What reaction forms the glycosidic linkage?
• Dehydration synthesis
21.
22. 3. Polysaccharides
Structure: Polymers of a few hundred or a few
thousand monosaccharides.
Functions: energy storage molecules or for
structural support:
23.
24. Starch is a plant storage form of energy, easily
hydrolyzed to glucose units
25. Cellulose is a fiber-like structural material made of
glucose monomers used in plant cell walls
26. Why is Cellulose so strong?
Glucose monomers are flipped to expose equal Hydroxyl
groups on either side of the chain
When Cellulose chains are lined up next to each other, they
Hydrogen Bond making a strong material that’s difficult to
break!
27.
28. Glycogen is the animal short-term storage form
of energy
Glucose monomers
29. Chitin is a polysaccharide used as a structural
material in arthropod exoskeleton and fungal cell
walls.
30. B. LIPIDS
What are Lipids?
• Fats, phospholipids, steroids, waxes, pigments
• Hydrophobic (“hydro”=water; “phobic” = fearing)
• Consist mostly of hydrocarbons
• Do NOT consist of polymers
31. Functions of Lipids in living things:
• Energy storage
• membrane structure
• Protecting against desiccation (drying
out).
• Insulating against cold.
• Absorbing shocks.
• Regulating cell activities by hormone
actions.
32. 1. Structure of Fats (Triglycerides)
Consist of a single glycerol and usually three fatty
acids
Glycerol – an alcohol with three carbons
Fatty Acid - Long Hydrocarbon chains with a
Carboxyl group at one end.
33.
34. Saturated and Unsaturated Fats
Unsaturated fats :
• one or more double bonds
between carbons in the fatty
Oleic acid
acids allows for “kinks” in the
tails
• liquid at room temp cis double bond
(b) Unsaturated fat and fatty acid
causes bending
• most plant fats
Saturated fats:
• No double bonds in fatty acid
tails
• solid at room temp
• most animal fats
Stearic acid
(a) Saturated fat and fatty acid
37. Saturated fatty
acid
Unsaturated
fatty acid
Why are Unsaturated Fats better for
you than Saturated Fats?
38. 3. Phospholipids
Structure: Glycerol + 2 fatty acids + phosphate
group.
Function: Main structural component of
membranes, where they arrange in bilayers.
40. 4. Waxes
Function:
• Lipids that serve as coatings for plant
parts and as animal coverings.
41. 5. Steroids
Structure: Four carbon rings with no fatty acid tails
Functions:
• Component of animal cell membranes (Ex:
Cholesterol)
• Modified to form sex hormones
43. C. Proteins
What are Proteins?
• Chains of amino acid monomers connected by
peptide bonds
• Have a 3 dimensional globular shape
44. Examples of Protein Functions
Immune System
• Binding of antibodies (proteins) to foreign substances
Transport
• Membrane transport proteins that move substances across
cell membranes
• Hemoglobin carries oxygen, iron, and other substances
through the body.
Muscle Contraction
• actin and myosin fibers that interact in muscle tissue.
Signaling
• Hormones such as insulin regulate sugar levels in blood.
45.
46. Amino Acids
Monomers of polypeptides
• Molecules with carboxyl and amino groups
• Differ in their properties due to differing side
chains, called R groups
47. 20 different
amino
acids exist
The sequence of
amino acids and the
interactions of the
different amino acids
determine a proteins
shape
48. Peptide bonds connect amino acids to form
polypeptide chains
One or more polypeptide chains make up a
protein
49. Proteins are very complex! Their specific
structure determines their function.
HEMOGLOBIN: Transport of
ACTIN: Filament involved in
gases and iron in blood
muscle contraction
50. Four Levels of Protein Structure
Primary structure HN +
3
Gly ProThr Gly
Glu
Thr
Gly Amino acid
Amino end
Cys LysSeu
subunits
• Is the unique sequence of
LeuPro
Met
Val
Lys
Val
amino acids in a
Leu
Asp
AlaVal Arg Gly
Ser
Pro
Ala
polypeptide
Glu Lle
Asp
Thr
Lys
Ser
Lys Trp Tyr
Leu Ala
Gly
lle
Ser
ProPheHis
Glu His
Ala
Glu
Val
Ala Thr PheVal
Asn
lle
Thr
Asp Tyr Ala
Arg
Ser Arg Ala
GlyPro
Leu
Leu
Ser
Pro
SerTyr
Tyr
Thr Ser
Thr
Ala
Val o
Val
ThrAsnProLys
Glu c
o–
Figure 5.20 Carboxyl end
51. Secondary structure
• Is the folding or coiling of the polypeptide into a
repeating configuration resulting from hydrogen
bonding of amino with carboxyl groups
• Includes the α helix and the β pleated sheet
β pleated sheet
O H O H O O H
H H H H H
R
Amino acid C C N R C C N R C C N C C N
N N C N
subunits C N R CC R
C C R C R C C
H O H O H O H O
H H H
R R R R
O O C O C O
C C
H H H H
C N C N H C N C N H C N C N H C N C N
H H H H
C H O C H O C H O C H O C
R R R
R R
C H C H
N H O C N H O C
N
O C
H
O C
N H
α helix
C
H C R H R H C R H C R
N H O C N H
O C
O C N H O C N
C C H
R R H
H
Figure 5.20
52. Tertiary structure
• Is the overall three-dimensional shape of a
polypeptide
• Results from interactions between amino
acids and R groups
Hydrophobic
interactions and
CH CH van der Waals
CH22
H3C CH3 interactions
O
Hydrogen H H3C CH3 Polypeptide
bond O CH backbone
HO C
CH2 CH2 S S CH2
Disulfide bridge
O
CH2 NH3+ -O C CH2
Ionic bond
53. Quaternary structure
• Is the overall protein structure that results from the
aggregation of two or more polypeptide subunits
54. Chaperonins
• Are protein molecules that assist in the proper
folding of other proteins
Correctly
folded
Polypeptide
protein
Cap
Hollow
cylinder
Chaperonin Steps of Chaperonin 2 The cap attaches, causing the The cap comes
3
(fully assembled) Action: cylinder to change shape in off, and the properly
1 An unfolded poly- such a way that it creates a folded protein is
peptide enters the hydrophilic environment for the released.
Figure 5.23 cylinder from one end. folding of the polypeptide.
57. Enzymes
Are a type of protein that acts as a catalyst, speeding
up chemical reactions up to 10 billion times faster
than they would spontaneously occur.
58. Environmental Factors That Determine
Protein Conformation
Change in environment may lead to denaturation
of protein (pH, temperature, salinity, etc.)
Denatured protein is biologically inactive
Can renature if primary structure is not lost
60. D. Nucleic Acids : The stuff of
Genes
Nucleic acids store and transmit hereditary information
Genes
• Are the units of inheritance
• Program the amino acid sequence of polypeptides
• Are made of nucleic acids
61. Two Kinds of Nucleic Acids
DNA (Deoxyribonucleic acid)
• double stranded
• can self replicate
• makes up genes which code for proteins
is passed from one generation to another
RNA (Ribonucleic acid)
• single stranded
• functions in actual synthesis of proteins
coded for by DNA
• is made from the DNA template molecule
62.
63. 1. Nucleotide Monomer Structure
Both DNA and RNA are composed of nucleotide
monomers.
Nucleotide = 5 carbon sugar, phosphate, and
nitrogenous base
Deoxyribose in DNA Ribose in RNA
64.
65. 2. Building the Polymer
Phosphate group of one nucleotide forms strong
covalent bond with the #3 carbon of the sugar of
the other nucleotide.
66. DNA:
• Double helix
• 2 polynucleotide chains wound
into the double helix
• Base pairing between chains
with H bonds
•A-T
•C-G