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
In 1953 Stanley Miller simulated what were thought to be environmental
conditions in the prebiotic earth.
Figure 4-02
Fig. 4-2:
He created Building Block Molecules
EXPERIMENT
Water vapor
“Atmosphere
CH4 ”
Electrode
Condense
r
Cooled
water
containing
organic
molecules
H 2O
“sea”
Cold
water
Simple compounds: Formaldehyde & Hydrogen Cyanide
More Complex Molecules: Amino Acids & Hydrocarbons
Sample for
chemical analysis
Fig. 5.2a: Common
Features of Macromolecules
(a) Dehydration reaction: synthesizing a polymer
1
2
3
Unlinked monomer
Short polymer
Dehydration removes
a water molecule,
forming a new bond.
1
2
3
Longer polymer
4
Fig. 5.2b: Common
Features of Macromolecules
(b) Hydrolysis: breaking down a polymer
1
1
2
2
3
3
4
Chapter 5: Biological Building Block Molecules are
the units (Monomers) of 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?
Common Features of Macromolecules - Shape
Common Features of Macromolecules
Fig. 2.18:
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 are
the units (Monomers) of Macromolecules
Complex Polymer
(Macromolecule)
Polysaccharide
(Complex Carbohydrate )
Monomer
Simple Polymer
Monosaccharide
(Simple Sugar)
Oligosaccharide
Nucleotide
Oligonucleotide
Nucleic Acid
Amino Acid
Peptide
Polypeptide
Protein
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
Fig. 5.3a: Trioses
Aldose (Aldehyde Sugar)
Ketose (Ketone Sugar)
Trioses: 3-carbon sugars (C3H6O3)
Chiral
Carbon
D- because –OH
is on the right
D - Glyceraldehyde
Dihydroxyacetone
–OH is on the
right  D
D-Glyceraldehyde
–OH is on the
left  L
L-Glyceraldehyde
3 Chiral Carbons
4 Chiral Carbons
3 Chiral Carbons
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
CH2OH
CH2OH
Assume C’s at vertices
and H’s at ends of lines
OH-CH2
O
O OH
OH
OH
OH
OH
OH
α-D-Glucose
OH
OH
β-D-Glucose
O
OH
OH-CH2
O
OH
OH
CH2OH
OH
β-D-Fructose
OH
OH
β-D-Ribose
Figure 5.5a: Disaccharides
1–4
glycosidic
linkage
Glucose
Glucose
CH2OH
CH2OH
CH2OH
O
O
OH
OH
OH
Malt Sugar
Glucose-Glucose
OH
OH-CH2
OH
OH
OH
OH
O
O
O
OH
OH
CH2OH
CH2OH
O
HO
O
OH
Maltose
OH
O
OH
O
OH
OH
CH2OH
OH
Milk Sugar
Table Sugar
Galactose-Glucose
Glucose-Fructose
Figure 5.7: Polysaccharides
– Starch & Cellulose
(a) α and β glucose
ring structures
α Glucose
(b) Starch: 1–4 linkage of α glucose monomers
β Glucose
(b) Cellulose: 1–4 linkage of β glucose monomers
Fig. 5.6: Starch & Glycogen – Food Storage Polysaccharides.
Chloroplast Starch granules
Amylopectin
Amylose
(a) Starch:
1 µm
a plant polysaccharide
Mitochondria Glycogen granules
Glycogen
(b) Glycogen:
0.5 µm
an animal polysaccharide
LE 5-8
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
Structural Polysaccharides - Chitin
β (14) Glycosidic Bond – similar to cellulose
Chitin forms the hard exterior
exoskeleton of insects
It is also used to make
biodegradable surgical threads
Lipids
Lipids are a diverse group of molecules that
are primarily water-insoluble and include:
Fats
Triglycerides
Oils
Waxes
Phospholipids
Biological
Membranes
Steroids
Carotenoids
Fatty Acids
Acyl chain
(16 – 18
carbons)
Straight
conformation
Bent (kinked)
conformation
Fig 5.10:
Triglycerides
Triglycerides consist of 3 fatty acids bonded to the three
hydroxyl (-O-H) groups of a molecule of glycerol (ester bonds)
Dehydration (condensation) Reaction
Acyl chains can be saturated
or unsaturated
Fig 5.12:
(a) Saturated fat
Structural
formula of a
saturated fat
molecule
Stearic acid, a
saturated fatty acid
(b) Unsaturated fat
Structural formula
of an unsaturated
fat molecule
Oleic acid, an
unsaturated
fatty acid
cis double
bond causes
bending
Triglycerides
Hydrophobic tails
Hydrophilic head
Fig 5.12: Phospholipids
Choline
Phosphate
Glycerol
Fatty acids
Hydrophilic
head
Hydrophobic
tails
Fig 5.13 / 7.2: Phospholipids Assemble to Form Membrane Bilayers
Fig 7.2
Phospholipid bilayers form
impermeable membranes
that enclose and
compartmentalize cells
Fig 5.14: Steroids
are lipid molecules (water insoluble) based
on a hydrocarbon structure with four fused rings
The Polar -OH group makes
this molecule amphipathic
Complex Polymer
(Macromolecule)
Polysaccharide
(Complex Carbohydrate)
Monomer
Simple Polymer
Monosaccharide
(Simple Sugar)
Oligosaccharide
Nucleotide
Oligonucleotide
Nucleic Acid
Peptid e
Polypeptide
Protein
Amino Acid
Adenine
Phosphate
N-Glycosidic Bond
Adenosine 5’-monophosphate
(AMP)
Phosphoester
Bond
RNA
RiboNucleic Acid
DNA
DeoxyriboNucleic Acid
Fig. 5.26: The
5′ end
components of Nucleic Acids
Sugar-phosphate backbone
Nitrogenous bases
Pyrimidines
5′C
3′C
Nucleoside
Nitrogenous
base
Phosphodiester
Bond
Cytosine (C) Thymine (T, in DNA) Uracil (U, in RNA)
Purines
5′C
1′C
5′C
3′C
Phosphate
group
3′C
Sugar
(pentose)
Guanine (G)
Adenine (A)
(b) Nucleotide
3′ end
Sugars
(a) Polynucleotide, or nucleic acid
Deoxyribose (in DNA)
(c) Nucleoside components
Ribose (in RNA)
Fig. 5.28: 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