Campbell and Reece
Chapter 4
ORGANIC CHEMISTRY
Organic Chemistry
study of carbon compounds (most
also have hydrogen)
 range from small molecules
(methane has 4 atoms) to very large
one (proteins can have thousands of
atoms)

Major Elements of Life

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Carbon
Hydrogen
Oxygen
Nitrogen
Sulfur
Phosphorus
Carbon is very Versatile
 because C can form 4 covalent bonds
these 6 elements can form an almost
limitless # organic molecules
VITALISM
 Some credit Hippocrates
 Simply stated: there is a life force
outside physical & chemical laws
Jons Jakob Berzelius
 Swedish chemist in early 1800’s
 “Organic compounds come from
living things” (only )
 so inorganic compounds found only
in nonliving things
Fredrich WÖhler
 German chemist
 1828: synthesized urea in lab
(normally made in kidney)
 Did not convince Vitalists because he
1 reactant he used came from animal
blood
Urea
Hermann Kolbe
 Student of Wohler
 Synthesized urea using only
inorganic reactants…..
 Crushed Vitalism…..sorry Yoda
Origin of Life on Earth
 Stanley Miller, 1953
 Designed experiment trying to re-
create conditions on early Earth
 Hypothesized : abiotic synthesis of
organic compounds possible
Miller’s Experiment
 Closed system
 Flask of water (early seas) heated
 Water vapor rose to another higher
chamber containing “atmosphere”
 Sparks added (lightening)
 “rain” formed, cooled  material
collected analyzed
Miller’s Experiment
Miller’s Conclusion
 Complex organic compounds could
form spontaneously under
conditions thought to exist on early
Earth
Miller’s Results
 2008: re-analyzed some samples
from Miller’s experiments in the
1950’s
 Additional organic compounds
identified
Organic Chemistry
 Definition changed to:
 Study of Carbon Compounds
(regardless of origin)
Bonding with Carbon
 C has 4 valence e Bonds possible:
 4 single covalent bonds
 2 single & 1 double covalent bond
 2 double covalent bonds
 1 single & 1 triple covalent bond
Bonding with Carbon
Carbon Skeletons
 Carbon chains form the backbone of
most organic molecules
 These skeletons can be
 Straight
 Branched
Carbon Skeleton Variation
 In rings:
Carbon Skeleton Variation
 1 important source of molecular
complexity & diversity that
characterizes living organisms
Hydrocarbons
C&H
 Major components of petroleum
products (fossil fuels)
 When organism dies all water soluble
compounds wash away as it decays.
 Fats stay behind  hydrocarbons
 Burn fossil fuels because they release a
large amount of energy
Fossil Fuels
Isomers
 Cpds with same # and types of atoms
but they are arranged differently
 Different structures behave
differently
 3 types:
1. Structural Isomers
2. Cis/trans Isomers
3. enantiomers
Structural Isomers
 Differ in covalent arrangements of
their atoms
 Molecular formula same, structure
different
Structural Isomers
 # possibilities for different
arrangements of atoms increases
dramatically as carbon skeleton
increases in size
Cis-trans Isomers
 aka geometric isomers
 Carbons have covalent bonds with
same atoms but these atoms differ
in their spatial relationship
Cis-trans Isomers
 In cis groups are on same side of
Carbon
 In trans groups are across from each
other
Cis-trans Isomers
 The difference in cis-trans can
dramatically affect the biological
behavior of the molecule
Enantiomers
 Isomers that are mirror images of each other
 Differ in shape due to having asymmetric
carbon
Enantiomers
 Usually only 1 is biologically active
 Other 1 may have much milder effect
Functional Groups
 Portion of molecule that participates
in chemical reactions in a
characteristic way
 7 common, & very important
functional groups in organic
chemistry
HYDROXYL
-OH
 Make alcohols
 Properties:
1. Polar
2. Can for H-Bonds with water
(help cpd dissolve in water)
CARBONYL
-C=O
 Makes:
1. Ketones: if in middle of molecule
2. Aldehyde: if at end of molecule
 Properties:
1. can be isomers
2. ketoses/aldoses
CARBOXYL
-COOH
 Makes: organic acids
 Properties:
1. Can donate H+  COO2. Mostly found in cells in ionized
form (charge of -1) & called a
carboxylate ion
3. In amino acids
CARBOXYL
AMINO
-NH2
 Makes:
Amines
 Properties:
1. Acts as a base (can take H+)
2. Found in cells in ionized form
with +1 charge
3. in amino acids
AMINE
SULFHYDRYL
-SH
 Makes:
thiols
 Properties:
1. 2 –SH can react forming disulfide
bridges
 These bridges make hair curly
PHOSPHATE
-PO4
 Structure:
 2 O have (-) charge
 Makes:
 Organic phosphates
 Properties:
 Makes molecule polar (-1) charge when
in middle, (-2) when on end
 Can react with water  energy
PHOSPHATE
METHYL
-CH3
 Makes:
 Methylated compounds
 Properties:
 When attached to DNA, affects
expression of genes
 Attachment to Testosterone changes
biological effect compared to Estrogen
(without methyl group)
METHYL
ADENOSINE TRIPHOSPHATE
ATP
 Made of adenosine + 3 phosphate
groups
 When 3 phosphates in series, easy to
remove 3rd group with water
Hydrolysis of ATP