Carbon Chemistry
Macromolecules
Carbon




Carbon—The Backbone of
Biological Molecules
All living organisms are
made up of chemicals
based mostly on the
element carbon
Carbon Chains & Rings
ETC
skeletons of most organic
molecules
Importance of Carbon
70 to 95% of cells are water
 Carbon makes up the rest of the compounds.
 2/3 of our dry weight (mostly proteins)
 Organic compounds can range from the
simple (CO2 or CH4) to complex molecules,
like proteins.
 While the percentages of major elements do
not vary within or amongst species, variations
in organic molecules can distinguish even
between individuals of a single species.

Some Common Carbon Compounds
Isomers
Isomers
 Are molecules with the same molecular
formula but different structures and
properties
 Three types of isomers are
 Structural
 Geometric
 Enantiomers

H
H
C
H
(a) Structural isomers
H
H
H
H
H
H
C
C
C
C
C
H
H
H
H
H
X
(b) Geometric isomers
H
H
(c) Enantiomers
C
C
C
H
H
H
X
C
C
X
H
H
CO2H
CO2H
C
C
H
NH2
CH3
H
H
H
C
H
See fig 4.8 pg 63
H
X
C
C
H
H
NH2
CH3
H
Intro. Cont………
 Combinations
of carbon and hydrogen form
hydrocarbons, many of which we use:
Gasoline propane ect….
 Organic compounds also form biological
molecules: Macromolecules. Ex.
Carbohydrates, lipids, proteins, and nucleic
acids.
 These macromolecules are made from simple
sugars, amino acids, nucleotides, and fatty
acids.
Functional Groups of Carbon compounds.
 Functional
groups
 The number and arrangement of functional
groups help give each molecule its distinctive
properties
 There are 7 functional groups that are
important to the chemistry of life: hydroxyl,
carbonyl, carboxyl, amino, sulfhydryl, methyl,
and phosphate groups.
Functional Group Example
Hydroxyl Group

In a hydroxyl group (-OH)

Free radical
Carbonyl Group

A carbonyl group (=CO)

end of the skeleton = aldelhyde.

If not, then the compound is a ketone.
Carboxyl group
 A carboxyl
group (-COOH)
 Carboxylic acids
Amino Group
An amino group (-NH2)
 Amines are organic compounds with amino groups
Amino acids, the building blocks of proteins, have amino
and carboxyl groups.

Sulfhydryl group

A sulfhydryl group (-SH)
 Sulfhydryl groups help stabilize the structure of
proteins.
Phosphate group

A phosphate group (-OPO32-) consists of phosphorus
bound to four oxygen atoms (three with single bonds and
one with a double bond).
 Ex. ATP
Macromolecules Introduction
 Cells
join small molecules to form large
molecules.
 Macromolecules, thousands of atoms and
weigh over 100,000 daltons.
 The four major classes of macromolecules are:
carbohydrates, lipids, proteins, and nucleic
acids
 They have very complex structures esp.
proteins
The Synthesis and Breakdown of
Polymers

Condensation or dehydration synthesis
reactions
HO
1
3
2
H
Unlinked monomer
Short polymer
Dehydration removes a water
molecule, forming a new bond
HO
1
H
HO
2
H2O
3
4
H
Longer polymer
(a) Dehydration
reaction in the synthesis of a polymer
 Polymers
can disassemble by
 Hydrolysis
HO
1
2
3
4
Hydrolysis adds a water
molecule, breaking a bond
HO
Figure 5.2B
1
2
3
(b) Hydrolysis of a polymer
H
H2O
H
HO
H
Carbohydrates
 Carbohydrates
or sugars can be simple or
complex.
 Simple sugars are called Monosaccharides.
 Disaccharides
 Polysaccharides
 Carbs. Are the most numerous molecules in
life.
Monosaccharides
 CH2O.
 Ex.
Glucose,
Ribose
Disaccharides
Polysaccharides
 Polysaccharides
hundreds to thousands of
monosaccharides joined by glycosidic linkages
 One
function is to store energy or serve as
building materials for the cell or whole organism.
 Starch
composed entirely of glucose monomers.
(plants)
 Animals
too store glucose glycogen.
All about Shape
Cont.
 Chitin,
another important structural
polysaccharide
CH2O
H
O OH
H
H
OH H
OH
H
H
NH
C
O
CH3
(b) Chitin
Figure 5.10 A–C
forms the exoskeleton
of arthropods.
(c) Chitin is used to make a
strong and flexible surgical
thread that decomposes
after
the wound or incision heals.
Lipids or FATS
 Hydrophobic
 Lipids
have 1-3 fatty acids attached to a glycerol
molecule.
 There are saturated and unsaturated fats. Saturated
fats have double bond and unsaturated do not.
 Triglycerides -energy source.
 Phospholipids
 Sterols- they have no fatty acids. Ex. Cholesterol
Phospholipid Bilayer
Proteins
 Proteins
are influential in about everything
 Functions include storage, structural support,
transport of other substances, intercellular
signaling, movement, and defense against foreign
substances.
 Enzymes
 Humans have an estimated 200,000 various
proteins,
 Most structurally complex molecules known.
 Polymers of amino acids
Modeling Protein Stucture
Figure 5.1
Amino Acids
Amino Acid Polymers
Peptide bonds
OH
Peptide
bond
OH
CH2
H
SH
CH2
H
N

CH2
H
C C
N
H O
H
C
C
H
O
OH H
(a)
N
C
C
OH
H
O
DESMOSOMES
H2O
OH
DESMOSOMES
DESMOSOMES
CH2
H
H
H N
Figure 5.18
(b)
C
C
H
O
Amino end
(N-terminus)
Side chains
SH
Peptide
CH2 bond CH2
OH
N
H
C
C
H
O
N
C
C
H
O
Carboxyl end
(C-terminus)
OH
Backbone
Function of Proteins


depends on shape.
function depends on its capacity to recognize and bind to some
other molecule.
 AB, Enzymes, and NT all based on shape
An overview of protein functions
Structure ( See pg 82-84)

Chaperonins

Are protein molecules that assist in the proper
folding of other proteins
Polypeptide
Cap
Correctly
folded
protein
Hollow
cylinder
Chaperonin
(fully assembled)
Figure 5.23
Steps of Chaperonin
Action:
1 An unfolded polypeptide enters the
cylinder from one end.
2 The cap attaches, causing
3 The cap comes
the cylinder to change shape in off, and the properly
folded protein is
such a way that it creates a
hydrophilic environment for the released.
folding of the polypeptide.
Protein structure can change
 Changes.
 pH,
salt
concentration,
temperature, or
other factors
can unravel or
denature a
protein
 mutation Pg 48
How do we Know

X-ray crystallography helps determine protein
conformation.
 This technique requires the formation of a crystal
of the protein being studied.
 The pattern of diffraction of an X-ray by the atoms
of the crystal can be used to determine the location
of the atoms and to build a computer model of its
structure.
The Instructions for Life Nucleic Acids
There are two types of nucleic acids: ribonucleic
acid (RNA) and deoxyribonucleic acid (DNA).
 DNA gives direction for its own replication,
repair, and control.
 DNA also directs RNA synthesis and through
RNA, controls protein synthesis.
 Organisms inherit DNA from their parents.
Nucleic Acids
Nucleic acids are many nucleotides joined
together.
 Each nucleotide consists of three parts: a
nitrogen base, a pentose, 5 carbon, sugar, and a
phosphate group
 Pyrimidines have a single six-membered ring.
 CTU
 Purine have a six-membered ring joined to a fivemembered ring. So have 2 rings not 1
 AG
