Carbon and the Molecular
Diversity of Life
Organic Chemistry-the study of
carbon compounds.
Why is Carbon important?
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A cell is 70-95%, the rest is mainly
carbon-based compounds
Proteins, DNA, carbohydrates
Simple (CO2 and CH4) to large ones like
proteins with thousands of atoms and
molecular weights over 100K daltons
History
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Jöns Jakob Berzelius (Swedish)- first to
distinguish between organic and inorganic
compounds
Friedrich Wöhler (German, 1823)- first to
create urea from non-organic sources
Hermann Kolbe- refined Wöhler method
Stanley Miller (1953)- demonstrated the
spontaneous synthesis of organic compounds
from H2O, H2, NH3, CH4
Carbon-most versatile building
block of molecules. Why?
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The chemical characteristics of carbon
are a result of its configuration of
electrons
6 electrons: 2 in the first valence shell,
and 4 in the second.
Carbon has little tendency to gain or
lose electrons and form ionic bonds
Carbon-most versatile building
block of molecules. Why?
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Can form 4 single covalent bonds
Capable of forming double and triple
covalent bonds
Can combine with atoms of many
different elements
Emergent Properties of
Carbon
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Determined by tetravalent electron
configuration
Can form large, complex molecules
Forms isomers (same formula- different
structure)
Joins with polyatomic ions (functional
groups)
Molecular shape of carbon bonding
Carbon skeletons
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vary in length, double bonds,
branching, rings
Hydrocarbon
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organic molecule consisting only of
carbon and hydrogen. Major component
of petroleum.
Hydrocarbons are found as part of
organic molecules in living organisms
(ex: fat)
Hydrocarbons- are hydrophobic because
they are nonpolar
Store large amount of energy
Isomers
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Molecules with the same types and
quantities of atoms, but different spatial
arrangements (therefore different
properties)
Isomers
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Structural isomers- differ in the covalent
arrangements of their atoms
Geometric isomers- have same covalent
partnerships but differ in their spatial
arrangements
Enantiomers- mirror images of each
other
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Ex: Thalidomide
Functional Groups
(Polyatomic Ions)
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Small characteristic groups of atoms that are
bonded to the carbon skeleton
Have specific chemical and physical
properties
Form regions that are chemically reactive
Consistent from one organic molecule to
another
Determine the unique chemical properties of
the organic molecule in which they are found
Just how important are
functional groups?
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Closely examine the two organic
molecules in the picture.
What differences are there?
How significant are the consequences?
Functional groups (Polyatomic
ions)
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Hydroxyl (-OH)
Carboxyl (–COOH)
Carbonyl (-CO)
2 types: ketone
aldehyde
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Amino (-NH2)
Methyl (-CH3)
Sulfhydryl (-SH)
Phosphate (-PO4)
Hydroxyl (-OH)
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Alcohols
Action: polar, therefore water molecules
are attracted to the hydroxyl group- helps
dissolve organic compounds
Ex: sugars dissolve easily in water, ethanol
mixes with water
Carboxyl (–COOH)
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-COOH (Oxygen double bonded, and a
Hydroxyl group)
Carboxylic acids
Formic acid (HCOOH) substance ants
inject
Acetic acid- makes vinegar taste sour
Acid properties
Carbonyl (-CO)
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C=O
Aldehyde- at the end of the chain
Ketone- not at the end of the chain
Amino (-NH2)
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Called amines
Methyl (-CH3)
Sulfhydryl (-SH)
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Sulfur is related to Oxygen, both have
six valence electrons and form two
covalent bonds
Thiols- organic compounds containing
sulfhydryls
Phosphate (-PO4)
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Phosphoric acids H3PO4 loses two H ions
(results in two negative charges)
Transfer of energy between organic
molecules