Transcript Chemistry
Chemistry
Functional Groups
Organic Chemistry
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
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
Structural isomers
Geometric isomers
Enantiomers
Structural Isomers
Variation in covalent partners
Pentane has a straight skeleton and isopentane
has a branched skeleton
Same molecular formula C5H12
Geometric Isomers
Variation in arrangement about a double bond
Example: rhodopsin (in the retina) from one
geometric isomer to another
Enantiomers
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
A specific configuration of atoms commonly
attached to the carbon skeletons of organic
molecules and usually involved in chemical
reactions
Hydroxyl
-OH
Carbonyl
CO
Carboxyl
-COOH
Amino
-NH2
Sulfhydryl
-SH
Phosphate
-PO4-2 (-OPO3-2)
Methyl
-CH3
1.Hydroxyl Group (-OH)
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
example ethanol
2.Carbonyl Group ( CO)
consists of an oxygen atom joined
to the carbon skeleton by a
double bond
ketone - if not at the end
example: acetone
aldehyde -if the carbonyl group
is on the end of the skeleton
example: propanal
3.Carboxyl Group (-COOH)
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 electro negativities of
the two adjacent oxygen atoms
increase the dissociation of
hydrogen as an ion (H+)
Example: acetic acid (vinegar)
4. Amino Group (-NH2)
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
Example: amino acids
5. Sulfhydryl Group (-SH)
sulfur atom bonded to a
hydrogen atom and to the
backbone
thiols - organic molecules
with sulfhydryl
Sulfhydryl groups help stabilize
the structure of proteins
Example: amino acid Cysteine
6. Phosphate Group
(-OPO3-2)
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.
Example ATP
7. Methyl Group (-CH3)
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
Example: 5-Methyl cytidine
Activity
Identify the functional groups
H
C-N
H
H
Methylamine
H
H
H
H
O
Alanine
N-C-C
OH
H
CH3
Activity
Identify the functional groups
ATP (adenosine triphosphate)
The End