Biology 189 Vogel

1. MacromoleculesChapter 4-5
1
Macromolecules
Some molecules called macromolecules because of
their large size
Usually consist of many repeating units
Resulting molecule is a polymer (many parts)
Repeating units are called monomers
Some examples:
NucleotideDNA, RNANucleic Acids
Amino acidPolypeptideProteins
MonosaccharidePolysaccharideCarbohydrates
Glycerol & fatty acidsTriglycerideLipids
Subunit(s)ExampleCategory
These molecules
are more
obviously
polymers
Polymer Monomer

2. MacromoleculesChapter 4-5
2
You should be able to recognize
the following macromolecules
.
(Label the following as either fats, proteins, amino acids,
carbohydrates or nucleic acids)
a. ________ b. ________
c. ________
d. ________
e. ________ f. ________ g. ________

3. MacromoleculesChapter 4-5
3
How macromolecules are made and used.
Dehydration and Hydrolysis
Know:
a. Organic polymers are made via a metabolic process
called
Dehydration synthesis
b. Polymers are taken apart by a process called hydrolisis
(this name should remind you that one water molecule us
produced by this process.)

4. MacromoleculesChapter 4-5
4
Dehydration Synthesis Fig. 5.2 p69

5. MacromoleculesChapter 4-5
5
Hydrolysis of a polymer

6. MacromoleculesChapter 4-5
6Examples of the 4 classes of
macromolecules.
1 - Carbohydrates
I.Monosaccharides: (single sugar molecules)
Glucose - 6 carbon sugars used by animals and plants for cellular
respiration
 Ribose, deoxyribose – 5 carbon sugars which are components of
DNA and RNA
II. Disaccharides: (Two monosaccharides joined by dehydration)
Sucrose – common form of plant sugars (glucose + fructose)
III. Polysaccharides: (Polymers of monosaccharides)
• Starch, cellulose, chitin – storage and structural form of sugars.

7. 7Models for Representing
Glucose Molecules
Formula: C6H12O6

8. 8Synthesis Disaccharides
Maltose and Fructose

9. MacromoleculesChapter 4-5
9
Two general forms of Carbohydrates
1. Storage forms of carbohydrates.
Polymers of monosaccharides
Low solubility; not sweet to taste
Examples
Starch = Polymer of glucose
Used for short-term energy storage
Amylose = Plant starch (eg. corn starch)
- unbranched chain, or slightly branched
 Glycogen = Animal starch
- Highly branched
- in liver and muscles

10. 10
Starch structure
and function
Storage form of carbs in plants
Fig. 5.6 p72

11. 11
Glycogen structure
and function
Storage form of carbs in animals

12. MacromoleculesChapter 4-5
12
Structural forms of carbohydrates
I. Cellulose
- Long, coiled polymer of glucose
- Glucoses connected differently than in starch
- Structural element for plants
- Main component of wood and many natural fibers
- Indigestible by most animals
II. Chitin
- Polymer of glucose
- Each glucose with an amino group
- Very resistant to wear and digestion
- Arthropod exoskeletons, cell walls of fungi
III. Peptidoglycans
- Bacterial cell walls.

13. MacromoleculesChapter 4-5
13
2. Carbohydrates as structural materials
chitin
notes:
Carbohydrates for
structural material :
a. In plants, cellulose
b. In some animals
(insects and
crustaceans), chitin
c. In bacteria,
peptidoglycan.

14. 14Cellulose structure and Function
Notice alternate orientation
Fig. 5.7 p.71

15. 15
Starch
Exocyclic carbons
All on the same
Side!

16. MacromoleculesChapter 4-5
16
Carbohydrate summary:
1. Monosacharides: ex. Glucose, Fructose
2. Disacharides : Sucrose (glucose + fructose)
3. Polysacharides:
a) Starch (plants), Glycogen (animals) -Storage
b) Cellulose (structural in plants) –alternation of bond orientation
c) Chitin (structural in insects and crabs etc. )
d) Peptidoglycan (structural in bacteria).

17. MacromoleculesChapter 4-5
17Four Classes of Organics:
2 - Lipids
Insoluble in water
 Long chains of repeating CH2 units
 Renders molecule nonpolar
Types of Lipids
Cholesterol, Testosterone
Estrogen, Progesterone, etc
Component of plasma
membrane; hormonesSteroids
PhospholipidsComponent of plasma
membranePhospholipids
Fatty AcidsLong-term energy storage in
plants and their seeds“Oils”
TriglyceridesLong-term energy storage &
thermal insulation in animals“Fats”
CompoundsOrganismal UsesType
Di, and Triesters..Wear resistance; retain waterWaxes
TG’S

18. 18Types of Lipids:
I. Fatty acids
Saturated
A.
B.
Fig. 5.11 p75

19. MacromoleculesChapter 4-5
19Types of Lipids:
II. Triglycerides
Animals typically store fatty acids in groups
of 3 attached to a glycerol molecule.
Triglycerides (Fats)
Long-term energy storage
Backbone of one glycerol molecule
- Three-carbon alcohol
- Each has an OH- group
- Each fatty acid may be
 Saturated - no double bonds between carbons
 or Unsaturated - 1 double bonds between carbons
- Carboxylic acid at one end
- Carboxylic acid connects to –OH on glycerol in
dehydration reaction

20. 20Dehydration Synthesis of Triglyceride
from Glycerol and Three Fatty Acids

21. MacromoleculesChapter 4-5
21Types of Lipids:
III. Phospholipids
Phospholipids
Glycerol backbone
Two fatty acids attached instead of three
Third fatty acid replaced by phosphate group
- The fatty acids are nonpolar and hydrophobic (“hates water)
- The phosphate group is polar and hydrophilic (“likes water)
Molecules self arrange when placed in water
Polar phosphate “heads” next to water (= hydrophilic)
Nonpolar fatty acid “tails” overlap and exclude water
(hydrophobic)
Spontaneously form double layer & a sphere
(cell membrane)

22. 22Phospholipids Form Membranes
Polar head
Orients toward
water
Fig. 5.12
p76

23. MacromoleculesChapter 4-5
23Types of Lipids:
IV. Steroids & Waxes
Steroids
Cholesterol, testosterone, estrogen
Skeletons of four fused carbon rings
Waxes
Long-chain fatty acid bonded to a long-chain
alcohol
-High melting point
-Waterproof
-Resistant to degradation

24. MacromoleculesChapter 4-5
24
Steriods
Know this basic structure!!
Side chains will
vary

25. 25Waxes

26. 26Additional Wax structures

27. MacromoleculesChapter 4-5
27Four Classes of Organics:
3 -Proteins
Functions
a. Support – Collagen
b. Enzymes – Almost all enzymes are proteins
c. Transport – Hemoglobin; membrane proteins
d. Defense – Antibodies
e. Hormones – Many hormones; insulin
f. Motion – Muscle proteins, microtubules
(see fig. 5.13, p. 76)
Know these six functions of proteins

28. MacromoleculesChapter 4-5
28Protein Subunits:
The Amino Acids
There are 20 different amino acids that make
up proteins
All of them have basically the same structure
except for what occurs at the sidechain R
Proteins are polymers
of amino acids

29. 29Physical / Chemical properties of amino acids:
3 Main Groups
Nonpolar
1.
Fig. 5.16 p79

30. 30
2.
Polar
3.
charged

31. MacromoleculesChapter 4-5
31Proteins:
Making polypeptides from amino acids.
Amino acids joined together end-to-end
 Special name for this bond - Peptide Bond
- Can have 3 or 4 amino acids (AA) joined
together, or several thousand
 Characteristics of a protein are determined by
composition and sequence of AA’s
 Virtually unlimited number of proteins
Ex. 10 AA’s can have 1020 different sequences.

32. 32Synthesis of a Peptide
Dehydration synthesis forms a peptide bond between the
carboxyl group of one amino acid and the amino group
of another.
Or:
Taken apart (digestion)
by hydrolysis!

33. MacromoleculesChapter 4-5
33Protein Molecules:
Levels of Structure
Primary:
 Literally, the sequence of amino acids
 A string of beads (up to 20 different colors)
Secondary:
 The way the amino acid chain coils or folds
Tertiary:
 Overall three-dimensional shape of a polypeptide
 Describing how the coils and folds interact with
eachother
Quaternary:
 Consists of more than one polypeptide
 Like several completed knots glued together

34. 34Levels of Protein Organization
A. Primary structure

35. 35Levels of Protein Organization
B. Secondary Structure

36. MacromoleculesChapter 4-5
36
Protein Folding
nonpolar
polar
charged
Where in a protein
would you expect to
find each of these groups
of amino acids?

37. 37Levels of Protein Organization
C. Tertiary Structure
Hydrophobic interactions
-COOH--
Charged amino acids
Fig. 5.18 p81

38. 38Levels of Protein Organization
D. Quaternary Structure
1o
2o
3o
4o

39. 39Examples of Fibrous Proteins
Keratin
Fibroin
Beta-mercaptoethanol
used to add more
disulfide bonds
(between which amino
acids ?)
Alpha helices
Beta-pleated sheets
Fibroin

40. MacromoleculesChapter 4-5
40
Protein Folding Chaperones
Defective protein folding
Is involved in human
Disease:
Ex:
• Alzheimer's
• CJD –Creutzfeldt Jacobs
(“Mad Cow Disease”)

41. MacromoleculesChapter 4-5
41Four Classes of Organics:
4 -Nucleic Acids
Polymers of nucleotides (C,T, A, G, U)
Very specific cell functions
DNA (deoxyribonucleic acid)
- Double-stranded helical spiral (twisted ladder)
- Serves as genetic information center
- In the nucleus of cells in chromosomes.
RNA (ribonucleic acid)
- Part single-stranded, part double-stranded**
- Serves primarily in assembly of proteins (several types:
tRNA, mRNA, rRNA and snRNP’s)
- In nucleus and cytoplasm of cell

42. MacromoleculesChapter 4-5
42The Nucleotides of
Nucleic Acids
Three components:
1. 5 carbon ribose sugar
2. phosphate group
3. nitrogenous base group
Nucleotide subunits connected end-to-end to
make nucleic acid
Sugar of one connected to the phosphate of
the next
Sugar-phosphate backbone

43. MacromoleculesChapter 4-5
43The Structure of
Nucleic Acids
Nucleotide subunits
connected end-to-end
to make nucleic acid
Sugar of one
connected to the
phosphate of the next
Sugar-phosphate
backbone

44. 44
Nucleotides

45. 45DNA Structure
The double alpha-helix
structure of DNA that
was determined by
Watson and Crick
1953

46. 46RNA Structure
RNA is mostly single
stranded or folds back
on itself to form double
stranded structures
Called “Stem-loops”

47. MacromoleculesChapter 4-5
47
NoYesHelix
Interprets genetic info;
protein synthesis
Heredity; cellular
control centerFunction
Cell nucleus and
cytoplasm
Chromosomes of cell
nucleusWhere
Comparison of DNA & RNA
Mostly single strandedDouble-stranded;
Pairing across strandsStrands
Cytosine, guanine;
adenine, uracil
Cytosine, guanine;
adenine, thymineBases
RiboseDeoxyriboseSugar
RNADNAFeature

48. MacromoleculesChapter 4-5
48Other Nucleic Acids
ATP – the energy currency of cells
ATP (adenosine triphosphate) is composed of
adenine, ribose, and three phosphates
In cells, one phosphate bond is hydrolyzed –
Yields:
The molecule ADP (adenosine diphosphate)
An inorganic phosphate molecule pi
Energy
Other energy sources used to put ADP and pi
back together again

49. 49ATP
The three “high energy” phosphate bonds of ATP are what
Make this molecule so useful in many enzymatic reactions.

50. MacromoleculesChapter 4-5
50
Review
Organic vs Inorganic
Functional Groups / Isomers
Macromolecules
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic Acids
– covalent C, O, H, N versus ionic metals and salts
-Amino, carboxyl, phosphate, sulhydryl.
-Iosomers = same formula, different structure
-starch, glycogen, (made from polymerized glucose)
-Cellulose, chitin = structural forms.
-fatty acids  3 together form triglycerides, 2 together + phosphate form
A phospholibid (membranes), can be saturated or unsaturated, steroids
Are different (shape) , Waxes = long chain fatty acids + alcohols
- Chains of 20 different amino acids linked by peptide bonds
-Chains of 4 different nucleotides linked by a sugar-phosh
Backbone, DNA = double stranded genetic material, RNA =
primary function in interpreting genenetic code into protei