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I. Chapter 5 Summary
A. Simple Sugars (CH2O)n:
1. One C contains a carbonyl (C=O) rest contain -OH
2. Classification by functional group: aldoses & ketoses
3. Classification by number of C's: trioses, pentoses, hexoses
4. Stereochemistry: all sugars have D conformation
5. Cyclic structure: -OH bonds to carbonyl carbon ==> 5- or 6-member ring
B. Disaccharides: 2 simple sugars joined by "glycosidic" bond between OH of one and carbonyl of another
1. Table sugar
2.
Maltose
3. Lactose
C. Polysaccharides
1. Food Storage: starch and glycogen are polymers of glucose
2. Structural: cellulose is polymer of glucose
3. Differ in conformation of carbonyl C where sugars are joined
II. Nucleotides & Nucleic Acids
A. Nucleotides: Base-sugar-phosphate
B. Nucleic Acids
1. Nucleotide polymer connected by phosphodiester bonds
2. RNA (RiboNucleic Acid)-nucleotides contain ribose sugar
3. DNA (DeoxyriboNucleic Acid)-nucleotides contain 2!-deoxy-ribose sugar
III. Lipids
A. Glycerides
1. Triglycerides: 3 fatty acids bonded to 3 -OH's of glycerol by ester bonds
2. Phospholipids: Diglycerides and Amphipathic (have polar and nonpolar
groups)
3. Phospholipid bilayer
B. Cholesterol-sterol lipid
Fig. 4.2: In 1953 Stanley Miller simulated what were thought to be
environmental conditions in the prebiotic earth.
Figure 4-02
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Chapter 5: Biological Building Block Molecules
(Monomers)
Monomers) and Macromolecules
Complex Polymer
(Macromolecule)
Polysaccharide
(Complex Carbohydrate)
Monomer
Simple Polymer
Monosaccharide
(Simple Sugar)
Oligosaccharide
Nucleotide
Oligonucleotide
Nucleic Acid
Amino Acid
Peptide
Polypeptide
Protein
What do Macromolecules Do?
Carbohydrates & Lipids:
Important Functions
fuel molecules for energy
Nucleic Acids:
structural roles
Store, Transmit, and Decode Hereditary Information
(also some structural roles)
Proteins:
Perform an incredible number of functions!
structural proteins
enzymes
storage proteins
contractile & motor proteins
transport proteins
hormones & signaling molecules
receptor proteins
defense proteins
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Fig. 5.2: Common
Features of Macromolecules
1. Proteins, carbohydrates and nucleic acids are complex
polymer molecules created by joining together building
blocks called monomers
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6
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Monomers are linked by a condensation reaction
(a dehydration reaction that produces H2O)
Fig. 5.2 Common
Features of Macromolecules
2. Protein, carbohydrate and nucleic acid polymer molecules
are broken down into monomers by hydrolysis of the bonds
between monomers
Hydrolysis adds a water
molecule, breaking a bond
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Common Features of Macromolecules
3. Protein, carbohydrate and nucleic acid polymer molecules
can fold into complex 3-dimensional shapes (specific shape
depends on sequence of monomers)
Ionic bonds, Hydrogen bonds and Van der Waal’s
interactions are important in specifying and maintaining shape
Common Features of Macromolecules
4. Protein, carbohydrate, lipids and nucleic acids can associate
with each other and with other types of molecules via
specific intermolecular interactions
Molecular shape, Ionic bonds, Hydrogen bonds and
Van der Waal’s interactions are important to
determine strength and specificity of interactions
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Fig. 2.17:
Important Concept
The function of a macromolecule is determined by its
Molecular Shape (conformation) & Composition
Macromolecules such as proteins work by
interacting with other molecules. These interactions
depend on the molecules having complementary shapes that
fit together (like a lock and key)
Chapter 5: Biological Building Block Molecules
(Monomers)
Monomers) and Macromolecules
Complex Polymer
(Macromolecule)
Polysaccharide
(Complex Carbohydrate )
Monomer
Simple Polymer
Monosaccharide
(Simple Sugar)
Oligosaccharide
Nucleotide
Oligonucleotide
Nucleic Acid
Amino Acid
Peptide
Polypeptide
Protein
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Carbohydrates:
Contain Carbon,
Carbon, Hydrogen and Oxygen in the ratio
CH2O
Monomers:
The simplest Carbohydrates are the Simple Sugars, these
are classified by:
Type of Carbonyl group  Ketone  Ketose
Aldehyde  Aldose
or by
O
R-C-R
O
R-C-H
Number of Carbon atoms:
3 C’s  Triose
4 C’s  Tetrose
5 C’s  Pentose
6 C’s  Hexose
Note: suffix …ose indicates a sugar
Aldose
Trioses
Ketose
All sugars, except Di-hydroxy acetone, can have D or L
optical isomers, although only the D isomers exist naturally.
L-Glyceraldehyde
D-Glyceraldehyde
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Common Simple Sugars
Trioses
Pentoses
Hexoses
Fig. 5.4a: Linear
and ring forms of glucose
Pentoses and Hexoses form ring structures in water when one of
the –OH groups forms a bond to the carbonyl group
Linear and
ring forms
2 forms, β and α
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Figure 5.5a: Disaccharides
1–4
glycosidic
linkage
Maltose
Glucose
Glucose
Disaccharides contain two simple
sugars joined by a Glycosidic Bond
Common Disaccharides
Malt Sugar
Glucose-Glucose
Milk Sugar
Galactose-Glucose
Table Sugar
Glucose-Fructose
Polysaccharides (Glycans
):
(Glycans):
Starch and Glycogen: Fuel storage polysaccharides
α (14) Glycosidic Bond
Cellulose: Structural polysaccharide
β (14) Glycosidic Bond
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LE 5-6
Fig.
5.6: Food Storage Polysaccharides - Starch and Glycogen
Chloroplast
Starch
Mitochondria Glycogen granules
0.5 µm
1 µm
Amylopectin
Amylose
Starch: a plant polysaccharide
LE 5-8
Glycogen
Glycogen: an animal polysaccharide
Fig. 5.8: Structural Polysaccharides - Cellulose
Cellulose microfibrils
in a plant cell wall
Cell walls
Microfibril
0.5 µm
Plant cells
Cellulose
molecules
β Glucose
monomer
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Structural Polysaccharides - Chitin
β (14) Glycosidic Bond
Chitin forms the hard
exterior exoskeleton of
insects
It is also used to make
biodegradable surgical
threads
Nucleotides / Nucleic Acids
Complex Polymer
(Macromolecule)
Polysaccharide
(Complex Carbohydrate)
Monomer
Simple Polymer
Monosaccharide
(Simple Sugar)
Oligosaccharide
Nucleotide
Oligonucleotide
Nucleic Acid
Amino A c i d
Peptid e
Polypeptide
Protein
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Nucleotides:
Adenine
consists of three components:
•Nitrogenous base, Adenine in this
example
•A sugar: ribose or 2’-deoxyribose
•Phosphate
Phosphate
N-Glycosidic Bond
Adenosine 5’-monophosphate
(AMP)
Phosphoester
Bond
RNA
DNA
Fig. 5.26a: The components of Nucleic Acids
5′ end
Nucleoside
Nitrogenous
base
Phosphodiester
Bond
Phosphate
group
Pentose
sugar
Nucleotide
3′ end
Polynucleotide, or Nucleic Acid
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Fig. 5.26b: Nucleoside Components
Nitrogenous bases
Pyrimidines
Cytosine
C
Thymine (in DNA) Uracil (in RNA)
U
T
Purines
Guanine
G
Adenine
A
Pentose sugars
Deoxyribose (in DNA)
Ribose (in RNA)
Nucleoside components
Fig. 5.27: The DNA double helix and its replication.
5′ end
3′ end
Sugar-phosphate
backbone
Base pair (joined by
hydrogen bonding)
Old strands
Nucleotide
about to be
added to a
new strand
5′ end
New
strands
5′ end
3′ end
5′ end
3′ end
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Lipids
Lipids are a diverse group of molecules which
are primarily water-insoluble and include:
Fats
triglycerides
Oils
Waxes
Phospholipids
Biological
Membranes
Steroids
Carotenoids
Fatty acids are the building blocks of lipids
Fatty Acids
Saturated fatty acids:
No double bonds between
adjacent carbon atoms
Unsaturated fatty acids:
One or more double bonds
between adjacent carbon
atoms
Acyl chain
(16 – 18
carbons)
Straight
conformation
Bent (kinked)
conformation
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Fig 5.11 & 5.12:
Triglycerides
Triglycerides consist of 3 fatty acids bonded to the three
hydroxyl (-O-H) groups of a molecule of glycerol (ester bonds)
Fats = triglycerides from
animals with mostly saturated
fatty acids
(condensation reaction)
Acyl chains can be saturated
or unsaturated
Oils = triglycerides from
plants with mostly unsaturated
fatty acids
Fig 5.13: Phospholipids
Hydrophilic
head
2
Hydrophobic
tails
Phospholipds are amphipathic molecules (contain both
hydrophilic and hydrophobic parts)
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Fig 5.14 / 7.2: Phospholipids Assemble to Form Membrane Bilayers
Fig 7.2
Phospholipid bilayers form
impermeable membranes
that enclose and
compartmentalize cells
Steroids are lipid molecules (water insoluble) based
on a hydrocarbon structure with four fused rings
Cholesterol is the most
common steroid and is
found in membranes
Cortisol,
Estrogen and
Testosterone
are steroid
hormones
The Polar -OH group makes
this molecule amphipathic
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