Transcript Organic Notes for Chapter 4 and 5

Organic Chemistry
Chapters 4 and 5
Chemical Compounds in
Living Things
In varying combinations, the elements
C, H, O, and N make up practically
all the chemical compounds in living
things
C easily forms covalent bonds that are
strong and stable. How many bonds
can it make? 4
Organics
Anything that has C and at least one H
is considered organic
Oxygen is also usually included
Exception: Methane CH4
Hydrocarbons
A molecule that just has a basic C
skeleton with H filling all of the
covalent binding sites is a
hydrocarbon
They store E
Ex: gasoline
Nonpolar
Organic Variations
 Organics can vary by their shape
 Molecules made of the same number
and type of atoms, but arranged in
different ways, are called isomers
(same-part)
 Three basic types
 Structural
 Geometric
 Enantiomers (Optical)
Structural Isomers
 Differ in covalent arrangement of
their atoms
Butane and ISObutane
Geometric Isomers
 Have identical covalent bonds,
but differ in the order in which the
atoms are arranged in space;
usually around a double bond
Enantiomers
 Mirror images of each other
 Because of their three-dimensional
structure, they cannot be superimposed
no matter how they are rotated
Organic Variations
 Organics can vary by the “danglies” off
of the C skeleton
 A change in placement or type of
functional group can change the effect
of the overall molecule

Estradiol vs. Testosterone in vertebrates
Functional groups
 Hydroxyl
 Carbonyl
 Carboxyl
 Amino
 Sulfhydryl
 Phosphate
Hydroxyl Groups
 –OH
 Polar because electronegative oxygen
attracts covalent e-s
 Makes the O-molecule water soluble
 Found in alcohols and sugars
 Can give the molecule an –ol ending
 Ethanol, Propanol
 Just because it has an –OH doesn’t mean
that it’s an alcohol
 –OH covalent bonds usually to C
 OH ionic bonds usually to a metal
Carbonyl Groups
 C double bonded to O
 Water soluble due to
electronegative O
 An aldehyde if at end of a C chain
 A ketone if attached to an “interior”
C
Carboxyl Groups
 COOH
 C double bonded to O; single bonded
to OH
 Highly polar; therefore water soluble
 Acts as a weak acid (releases H+)
 Found in amino acids and fatty acids
Amino Groups
 N bonded to two H
 Weakly basic (accepts H+)
 Water soluble (polar molecule)
 Found in amino acids
Sulfhydryl Groups
 –SH
 Also called thiols
 Similar to hydroxyls (water soluble);
notice where S is on the periodic table
 Help form 2O and 3O protein structure
(stabilizes internal protein structure at
“disulfide bridges”)
 Found in amino acid cysteine
 Perms create disulfide bridges – makes
hair curly and stinky
Phosphate Groups
 –PO42 Weakly acidic; one or two H+ ions can
be released
 Water soluble
 Found in ATP, other nucleotides, DNA,
RNA, many proteins, and
phospholipids
Fig. 4.10
Page 64-65
Polymerization
 Large compounds are formed from
strings of smaller compounds
 The small compounds are called
MONOMERS
 When joined together, they are call
POLYMERS
 We only have 26 letters in the
alphabet, but we join those letters in
long and short ways to make an infinite
number of words
Condensation (Dehydration
Synthesis)
Monomer
OH
H
Polymer
H
20
OH
Monomer
Removal
of Water
Hydrolysis (Hydration)
Monomer
OH
H
Polymer
Addition of
Water
H
20
OH
Monomer
Carbohydrates
 Functions
 E storage (starch, glycogen)
 Structure/support (chitin, cellulose)
 Membrane receptors
(glycoproteins)
 Monomers = monosaccharides
 Adding monomers creates di- and
polysaccharides
Lipids
 Functions
 E storage (fats, oils)
 Membranes (phospholipids)
 Triglycerides: glycerol and 3 fatty
acids
 Saturated: all single bonds
 Unsaturated: some double bonds
Glycerol +
3 Fatty acids
Triglyceride
+
3 Water
Lipids
 Sterols
 4 interconnecting C rings
 Vitamin D, cortisone, testosterone,
estrogen, and cholesterol
 Cholesterol produced by liver
during breakdown of saturated fats
 Excess cholesterol can accumulate
in inner lining of blood vessels
 Avoid too much saturated fat
Lipids
 Waxes
 Fatty acids combined with either
alcohols or other hydrocarbons
 Usually hard
 Water-repellent, which helps to
waterproof fur, feathers, and
leaves
Proteins
 Functions
 Transport (hemoglobin)
 Muscle action (myosin, actin)
 Blood clotting (thrombin, fibrin)
 Support (collagen, elastin)
 Immunity (antibodies)
 Rxn catalysis (enzymes)
 Monomers = amino acids
Proteins
 Conformation: 3-D structure
O
 1 : sequence of amino acids
O
 2 : H-bonds between nonadjacent
carboxyl and amino groups
• Alpha helix
• Beta-pleated sheets
O
 3 : disulfide and ionic bonds
between R groups
O
 4 :H- and ionic bonds between
separate polypeptides
Nucleic Acids
 Functions
 Transfer of genetic information
 Monomers = nucleotides
 Nucleotides:
 Nitrogenous base
 5-C sugar
 Phosphate group