Carbon Compounds
Isomers
Monkemeier
Honors Biology
Carbon Skeletons
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The framework of biological molecules
consists predominately of carbon atoms
bonded to other carbon atoms or atoms of
oxygen, hydrogen, nitrogen or sulfur.
Carbon skeletons form the backbone of
biological molecules
Carbon skeletons occur in chains, branched
chains or rings.
Four Major Types of Biological
Molecules and Carbon Skeletons!
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The four major types of biological molecules:
carbohydrates, lipids, nucleic acids, and
proteins.
Carbon chains often contain hydrogen. The
C-C and C- H bonds are nonpolar since
carbon and hydrogen have similar
electronegativities.
Functional Groups
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Functional Groups are specific groups of
atoms (that are covalently bonded together)
that have definite chemical properties that
they retain no matter where they occur.
Functional Groups attached to a “carbon –
chain” molecule provide that molecule with
their definite chemical properties!
Functional Groups
Carbon Skeletons and Isomers!
 Isomers
are compounds with
the same chemical formula but
different structural
arrangements.
Structural Isomers
 When
differences exist in in the
actual structure of the carbon
skeleton the compounds are
structural isomers.
Sterioisomers
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These molecules have the same carbon
skeleton but differ in how the groups
attached to this skeleton are arranged.
Enantiomers
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A subcategory of sterioisomers that are
mirror images of each other.
Chiral molecules are mirror images of each
other.
Chiral molecules are characterized by their
effect on polarized light and chiral molecules
rotate to the left or right.
Chiral Molecules
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Levorotatory rotates the
molecule to the left and
is designated L
Dextrorotatory rotates
the molecule to the
right and is designated
D.
Chiral Molecules and Living Systems
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Living systems tend to produce only a single
enantiomer of the tow possible forms (L or
D); for example, in most organisms:
D – Sugars
L – amino Acids
HOW?
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How do living systems build huge polymers
like starch or enzymes?
Instead of building them one atom at a time,
they build them one monomer at a time.
Monomers are molecules that act as
subunits that when put together form
polymers (large macromolecules).
Monomers to Polymers
Monomers to Polymers
Dehydration Synthesis: Monomers to
Polymers
Polymers back to Monomers:
Hydrolysis
The Four Major Categories
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Carbohydrates, Lipids, Proteins and nucleic acids
are all built and broken down using the SAME TWO
REACTIONS.
Dehydration Synthesis (aka condensation) forms
bonds between monomers.
Hydrolysis (sometimes aka decomposition) breaks
the bonds between monomers
In both reactions: DO NOT FORGET THE ROLE of
WATER!
NEXT TIME!
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The four major categories of
macromolecules!
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