HO
1
2
3
H
Short polymer
HO
Unlinked monomer
Dehydration removes a water
molecule, forming a new bond
HO
2
1
H
3
H2O
4
H
Longer polymer
(a) Dehydration reaction in the synthesis of a polymer
HO
1
2
3
4
Hydrolysis adds a water
molecule, breaking a bond
HO
1
2
3
H
H
H2O
HO
H
(b) Hydrolysis of a polymer
1
Trioses (C3H6O3)
Pentoses (C5H10O5)
Hexoses (C6H12O6)
Glyceraldehyde
Ribose
Glucose
Galactose
Dihydroxyacetone
Ribulose
Fructose
2
(a) Linear and ring forms
(b) Abbreviated ring structure
3
1–4
glycosidic
linkage
Glucose
Glucose
Maltose
(a) Dehydration reaction in the synthesis of maltose
1–2
glycosidic
linkage
Glucose
Fructose
Sucrose
(b) Dehydration reaction in the synthesis of sucrose
4
Chloroplast
Mitochondria Glycogen granules
Starch
0.5 µm
1 µm
Glycogen
Amylose
Amylopectin
(a) Starch: a plant polysaccharide
(b) Glycogen: an animal polysaccharide
5
(a)  and  glucose
ring structures
 Glucose
(b) Starch: 1–4 linkage of  glucose monomers
 Glucose
(b) Cellulose: 1–4 linkage of  glucose monomers
6
Cell walls
Cellulose
microfibrils
in a plant
cell wall
Microfibril
10 µm
0.5 µm
Cellulose
molecules
 Glucose
monomer
7
8
(a) The structure
of the chitin
monomer.
(b) Chitin forms the
exoskeleton of
arthropods.
(c) Chitin is used to make
a strong and flexible
surgical thread.
9
Fatty acid
(palmitic acid)
Glycerol
(a) Dehydration reaction in the synthesis of a fat
Ester linkage
(b) Fat molecule (triacylglycerol)
10
Structural
formula of a
saturated fat
molecule
Stearic acid, a
saturated fatty
acid
(a) Saturated fat
Structural formula
of an unsaturated
fat molecule
Oleic acid, an
unsaturated
fatty acid
(b) Unsaturated fat
cis double
bond causes
bending
11
Hydrophilic head
Hydrophobic tails
(a) Structural formula
Choline
Phosphate
Glycerol
Fatty acids
Hydrophilic
head
Hydrophobic
tails
(b) Space-filling model
(c) Phospholipid symbol
12
Hydrophilic
head
Hydrophobic
tail
WATER
WATER
13
14
15
Substrate
(sucrose)
Glucose
OH
Enzyme
(sucrase)
H2O
Fructose
HO
16
 carbon
Amino
group
Carboxyl
group
17
Nonpolar
Glycine
(Gly or G)
Valine
(Val or V)
Alanine
(Ala or A)
Methionine
(Met or M)
Leucine
(Leu or L)
Trypotphan
(Trp or W)
Phenylalanine
(Phe or F)
Isoleucine
(Ile or I)
Proline
(Pro or P)
Polar
Serine
(Ser or S)
Threonine
(Thr or T)
Cysteine
(Cys or C)
Tyrosine
(Tyr or Y)
Asparagine Glutamine
(Asn or N) (Gln or Q)
Electrically
charged
Acidic
Aspartic acid Glutamic acid
(Glu or E)
(Asp or D)
Basic
Lysine
(Lys or K)
Arginine
(Arg or R)
Histidine
(His or H)
18
Peptide
bond
(a)
Side chains
Peptide
bond
Backbone
(b)
Amino end
(N-terminus)
Carboxyl end
(C-terminus)
19
Groove
Groove
(a) A ribbon model of lysozyme
(b) A space-filling model of lysozyme
20
Antibody protein
Protein from flu virus
21
Primary
Structure
Secondary
Structure
Tertiary
Structure
Quaternary
Structure
 pleated sheet
+H N
3
Amino end
Examples of
amino acid
subunits
 helix
22
Hydrophobic
interactions and
van der Waals
interactions
Polypeptide
backbone
Hydrogen
bond
Disulfide bridge
Ionic bond
23
Polypeptide
chain
 Chains
Iron
Heme
 Chains
Hemoglobin
Collagen
24
Normal hemoglobin
Primary
structure
Val His Leu Thr Pro Glu Glu
1
2
3
4
5
6
7
Secondary
and tertiary
structures
 subunit
Function
Normal
hemoglobin
(top view)
Secondary
and tertiary
structures
1
2
3
Normal red blood
cells are full of
individual
hemoglobin
moledules, each
carrying oxygen.
6
7
 subunit

Sickle-cell
hemoglobin

Function

Molecules
interact with
one another and
crystallize into
a fiber; capacity
to carry oxygen
is greatly reduced.
10 µm
Red blood
cell shape
5
Exposed
hydrophobic
region

Molecules do
not associate
with one
another; each
carries oxygen.
4

Quaternary
structure

Val His Leu Thr Pro Val Glu


Quaternary
structure
Sickle-cell hemoglobin
Primary
structure
10 µm
Red blood
cell shape
Fibers of abnormal
hemoglobin deform
red blood cell into
sickle shape.
25
Denaturation
Normal protein
Renaturation
Denatured protein
26
Polypeptide
Correctly
folded
protein
Cap
Hollow
cylinder
Chaperonin
(fully assembled)
Steps of Chaperonin 2
Action:
1 An unfolded polypeptide enters the
cylinder from one end.
The cap attaches, causing the 3 The cap comes
cylinder to change shape in
off, and the properly
such a way that it creates a
folded protein is
hydrophilic environment for
released.
the folding of the polypeptide.
27
DNA
1 Synthesis of
mRNA in the
nucleus
mRNA
NUCLEUS
CYTOPLASM
mRNA
2 Movement of
mRNA into cytoplasm
via nuclear pore
Ribosome
3 Synthesis
of protein
Polypeptide
Amino
acids
28
5 end
Nitrogenous bases
Pyrimidines
5C
3C
Nucleoside
Nitrogenous
base
Cytosine (C)
Thymine (T, in DNA) Uracil (U, in RNA)
Purines
Phosphate
group
5C
Sugar
(pentose)
Adenine (A)
Guanine (G)
(b) Nucleotide
3C
Sugars
3 end
(a) Polynucleotide, or nucleic acid
Deoxyribose (in DNA)
Ribose (in RNA)
(c) Nucleoside components: sugars
29
5' end
3' end
Sugar-phosphate
backbones
Base pair (joined by
hydrogen bonding)
Old strands
Nucleotide
about to be
added to a
new strand
3' end
5' end
New
strands
5' end
3' end
5' end
3' end
30
31