Chemistry
Functional Groups
Organic Chemistry
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The study of carbon-containing compounds
Carbon atoms are the most versatile building blocks of
molecules
With a total of 6 electrons, a carbon atom has 2 in the
first shell and 4 in the second shell
Carbon usually completes its valence shell by sharing
electrons with other atoms in four covalent bonds
This tetravalence by carbon makes large, complex
molecules possible
Carbon Chains
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form the skeletons of most organic molecules
the skeletons may vary in length and may be straight,
branched, or arranged in closed rings
the carbon skeletons may also include double bonds
Isomers
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Structural isomers
Geometric isomers
Enantiomers
Structural Isomers
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Variation in covalent partners
pentane has a straight skeleton and isopentane
has a branched skeleton
same molecular formula C5H12
Geometric Isomers
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Variation in arrangement about a double bond
rhodopsin (in the retina) from one geometric
isomer to another
Enantiomers
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Variation in spatial arrangement, mirror images
enantiomers are possible if there are four different
atoms or groups of atoms bonded to a carbon
they are like left-handed and right-handed
versions
usually one is
biologically active,
the other inactive
Functional Group
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A specific configuration of atoms commonly
attached to the carbon skeletons of organic
molecules and usually involved in chemical
reactions
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Hydroxyl
Carbonyl
Carboxyl
Amino
Sulfhydryl
Phosphate
Methyl
-OH
CO
-COOH
-NH2
-SH
-PO4-2 (-OPO3-2)
-CH3
1.Hydroxyl Group (-OH)
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a hydrogen atom forms
a polar covalent bond
with an oxygen which
forms a polar covalent
bond to the carbon
skeleton.
Organic compounds with
hydroxyl groups are
alcohols and their names
typically end in -ol
2.Carbonyl Group ( CO)
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consists of an oxygen
atom joined to the
carbon skeleton by a
double bond
aldehyde -If the
carbonyl group is on
the end of the skeleton
ketone - if not at the end
3.Carboxyl Group (-COOH)
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carbon atom with a double
bond with an oxygen atom and
a single bond to a hydroxyl
group.
carboxylic acids - compounds
with carboxyl groups
Acidic properties - because the
combined electronegativities of
the two adjacent oxygen atoms
increase the dissociation of
hydrogen as an ion (H+)
4. Amino Group (-NH2)
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nitrogen atom attached to two
hydrogen atoms and the
carbon skeleton.
Amines - Organic compounds
with amino groups.
Basic properties - because
ammonia can pick up a
hydrogen ion (H+) from the
solution
5. Sulfhydryl Group (-SH)
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sulfur atom bonded to a
hydrogen atom and to the
backbone
thiols - organic molecules
with sulfhydryl
Sulfhydryl groups help stabilize
the structure of proteins
6. Phosphate Group
(-OPO3-2)
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Phosphorus bound to four
oxygen atoms (three with
single bonds and one with
a double bond).
Phosphate groups are anions
with two negative charges as
two protons have dissociated
from the oxygen atoms.
One function of phosphate
groups is to transfer energy
between organic molecules
7. Methyl Group (-CH3)
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Carbon bonded to 3 hydrogen
atoms. The methyl group may
be attached to a or a different
atom
Addition of methyl to molecule
changes its shape and function
Activity:
identify the function group
H
C-N
H
H
Methylamine
H
H
H
H
O
Alanine
N-C-C
OH
H
CH3
Activity
ATP (adenosine triphosphate)
The End