Transcript Functional Groups - Effingham County Schools

Carbon and the Molecular Diversity of Life
• Biological macromolecules – carbohydrates,
protein, lipids, and nucleic acids (DNA &
RNA) - are all composed of carbon atoms
• Other important elements include:
– Hydrogen (H)
– Oxygen (O)
– Nitrogen (N)
– Sulfur (S)
– Phosphorus (P)
Organic Chemistry
• Organic Chemistry is the study of carbon
compounds – compounds of living things
• Carbon has 4 valence electrons
–usually forms 4 covalent bonds with
other atoms
–allows molecules to branch off in up to
4 directions
–makes large, complex molecules
possible
Diversity of Organic Molecules
• Carbon atoms readily bond with each other,
producing chains or rings of carbon atoms
• Carbon chains form the backbones of most
organic molecules
• These carbon backbones can vary in length,
branching, placement of double bonds, and
location of atoms of other elements
• The variations in these skeletons contributes
to the complexity and diversity of living
matter.
Diversity of Organic Molecules
What is the name of compounds consisting
solely of carbon and hydrogen?
Hydrocarbons
• Organic molecules consisting of only
carbon and hydrogen
• Major component of petroleum (fossil fuels)
– partially decomposed remains of
organisms that lived millions of years ago
• Are hydrophobic because the bonds between
C and H are nonpolar
• Store a relatively large
amount of energy (fat is
stored energy for the
body)
Isomers
• Compounds that have the same molecular
formula, but different structural formulas;
therefore, different properties
• Three types: structural isomers, geometric
isomers, and enantiomers
• Structural isomers of butane, C4H10
Structural Isomers
Butane
Isobutane
Both have the
same molecular
formula, but
different structural
formulas
• Differ in the covalent arrangement of their
atoms
• C20H42 has 366,319 possible structural
isomers
• May differ in the placement of the double bond
Geometric Isomers
• Same covalent partnership, differ in spatial
arrangement
• Due to inflexibility of double bonds – do not
allow atoms to rotate about the axis
• The subtle difference in shape can
dramatically affect the biological activities of
the molecule
• Example – rhodopsin in the eye
Enantiomers
• Mirror images of each other
• Differ in spatial arrangement around an
asymmetric carbon (a carbon atom bonded
to 4 different kinds of atoms or groups of
atoms)
• Each enantiomer
may behave
differently in the
body
Functional Groups
• Components of organic molecules most
commonly involved in chemical reactions
• Attachments that replace one or more of the
hydrogens bonded to the carbon skeleton of
the hydrocarbon
• Behaves consistently from one organic
molecule to another
• Number and arrangement of
groups give each molecule its
unique properties
• Example: estradiol and
testosterone
Functional Groups
Hydroxyl Group
• Organic compounds containing hydroxyl are
alcohols
• Name usually ends in –ol (i.e. ethanol)
• Hydrophilic – soluble in water
Functional Group
Formula
Name of Compound
Example
Functional Groups
Carbonyl Group
• A carbon atom joined to an oxygen atom by a double
bond
• If the carbonyl group is on the end, the compound is an
aldehyde
• Anywhere else, the compound is a ketone (i.e. acetone)
• Hydrophilic – soluble in water
Functional Group
Formula
Name of Compound
Example
Functional Groups
Carboxyl Group
• An oxygen atom double-bonded to a carbon atom that is
also bonded to a hydroxyl group
• Compounds containing a carboxyl group are called
carboxylic acids or organic acids
• Hydrophilic – soluble in water
• Have acidic properties
Functional Group
Formula
Name of Compound
Example
Functional Groups
Amino Group
• A nitrogen atom bonded to two hydrogen atoms and to
the carbon skeleton
• Compounds containing an amino group are called
amines (i.e. glycine – an amino acid)
• Hydrophilic – soluble in water
• Have basic properties
Functional Group
Formula
Name of Compound
Example
Functional Groups
Sulfhydryl Group
• A sulfur atom bonded to an atom of hydrogen
• Compounds containing a sulfhydryl group are called
thiols
• Hydrophilic – soluble in water
• Interact to stabilize the structure of a protein
Functional Group
Formula
Name of Compound
Example
Functional Groups
Phosphate Group
• A phosphate ion covalently attached by one of its oxygen
atoms to the carbon skeleton
• Transfers energy between organic molecules (a process
exhibited in cellular respiration)
• Hydrophilic – soluble in water
Functional Group
Formula
Name of Compound
Example