Download Chapter 3 2015 - Franklin College

LE 4-4
Hydrogen
(valence = 1)
Oxygen
(valence = 2)
Nitrogen
(valence = 3)
Carbon
(valence = 4)
LE 4-5
Ethane
Propane
Butane
2-methylpropane
(commonly called isobutane)
Length
Branching
1-Butene
Double bonds
Cyclohexane
Rings
2-Butene
Benzene
LE 4-7
Structural isomers differ in covalent partners, as shown in
this example of two isomers of pentane.
cis isomer: The two Xs
are on the same side.
trans isomer: The two Xs
are on opposite sides.
Geometric isomers differ in arrangement about a double
bond. In these diagrams, X represents an atom or group of
atoms attached to a double-bonded carbon.
L
isomer
D
isomer
Enantiomers differ in spatial arrangement around an
asymmetric carbon, resulting in molecules that are mirror
images, like left and right hands. The two isomers are
designated the L and D isomers from the Latin for left and
right (levo and dextro). Enantiomers cannot be
superimposed on each other.
LE 4-10aa
STRUCTURE
(may be written HO—)
Ethanol, the alcohol present in
alcoholic beverages
NAME OF COMPOUNDS
Alcohols (their specific names
usually end in -ol)
FUNCTIONAL PROPERTIES
Is polar as a result of the
electronegative oxygen atom
drawing electrons toward itself.
Attracts water molecules, helping
dissolve organic compounds such
as sugars (see Figure 5.3).
LE 4-10ab
Acetone, the simplest ketone
STRUCTURE
EXAMPLE
Acetone, the simplest ketone
NAME OF COMPOUNDS
Propanal, an aldehyde
Ketones if the carbonyl group is
within a carbon skeleton
FUNCTIONAL PROPERTIES
Aldehydes if the carbonyl group is
at the end of the carbon skeleton
A ketone and an aldehyde may
be structural isomers with
different properties, as is the case
for acetone and propanal.
LE 4-10ac
STRUCTURE
EXAMPLE
Acetic acid, which gives vinegar
its sour taste
NAME OF COMPOUNDS
Carboxylic acids, or organic acids
FUNCTIONAL PROPERTIES
Has acidic properties because it is
a source of hydrogen ions.
The covalent bond between
oxygen and hydrogen is so polar
that hydrogen ions (H+) tend to
dissociate reversibly; for example,
Acetic acid
Acetate ion
In cells, found in the ionic form,
which is called a carboxylate group.
LE 4-10ba
STRUCTURE
EXAMPLE
Glycine
Because it also has a carboxyl
group, glycine is both an amine and
a carboxylic acid; compounds with
both groups are called amino acids.
NAME OF COMPOUNDS
Amine
FUNCTIONAL PROPERTIES
Acts as a base; can pick up a
proton from the surrounding
solution:
(nonionized) (ionized)
Ionized, with a charge of 1+,
under cellular conditions
LE 4-10bb
STRUCTURE
EXAMPLE
(may be written HS—)
Ethanethiol
NAME OF COMPOUNDS
Thiols
FUNCTIONAL PROPERTIES
Two sulfhydryl groups can
interact to help stabilize protein
structure (see Figure 5.20).
LE 4-10bc
STRUCTURE
EXAMPLE
Glycerol phosphate
NAME OF COMPOUNDS
Organic phosphates
FUNCTIONAL PROPERTIES
Makes the molecule of which it
is a part an anion (negatively
charged ion).
Can transfer energy between
organic molecules.
Table 4.1 Functional Groups of Organic Compounds
LE 4-9
Estradiol
Female lion
Testosterone
Male lion
Common Elements found in living
organisms
Molecular Composition of 2 cells
LE 5-2a
Short polymer
Unlinked monomer
Dehydration removes a water
molecule, forming a new bond
Longer polymer
Dehydration reaction in the synthesis of a polymer
LE 5-2b
Hydrolysis adds a water
molecule, breaking a bond
Hydrolysis of a polymer
The molecules of life
• Carbohydrates (C,H,O)-monomer is a
monosaccharide and polymers are
polysaccharides
• Lipid-(C,H,O)-in triglycerides (polymer) the 2
monomers are glycerol and fatty acids. Steroids
lipids are not monomers or polymers
• Proteins (C,H,O,N,S)-monomers are amino
acids and the polymers are polypeptides
• Nucleic acids (C,H,O,N,P)-monomers are
nucleotides and the polymers are
polynucleotides.