Chapter 4: Carbon and Molecular Diversity
I. The Foundations of Organic Chemistry: The study of carbon
compounds
A. A single cell is composed of 70-95% water
1. Most of the rest consists of carbon-based compounds
2. Proteins, DNA, carbohydrates that distinguish living
matter from inanimate material
B. Organic chemistry:
1. % of C, O, H, N, S, P are uniform from individual to
individual and from species to species
a. Atoms in an organic molecule can be arranged
many different ways
C. Know the terms and contributions made by the following:
(Table Activity)
1. George Washington Carver
2. Jons Jakob Berzelius (Swedish
3. Friedrich Wohler
a. Famous statement and argument
4. Hemann Kolbe (Wholer’s student)
5. 1953 Stanley Miller (American) abiotic synthesis:
D. Vitalism
E. Mechanism
II. The Versatility of Carbon in molecular architecture
A. The chemical characteristics of an atom depends on its
configuration of electrons
1. Forms 4 covalent bonds: tetra-valence
a. Makes large complex molecules possible
2. 4 single bonds (109o) tetrahedron
a. CH4
b. C2H6 (2 overlapping tetrahedrons)
1
B. Molecules are 3 dimensional; shape determines function
1. CO2 (Often considered inorganic)
2. Urea CO(NH2)2
III. Variation in C Skeletons
A. C chains (C and H)
1. Vary in length
2. Branched or unbranched
3. Double bonds in various locations
4. Arranged in rings
5. Atoms of other elements can be bonded to the
skeletons at available sites
B. Hydrocarbons: Organic molecules consisting only of C
and H
1. Not prevalent in living organisms
a. Many of cell’s organic molecules have regions
consisting only of C and H
1. Fats: Hydrocarbon tail attached to nonhydrocarbon component (head)
a. Stored in adipose cells
b. 3 hydrocarbon tails attached to head
containing O
2. Non-polar bonds: Hydrophobic
3. Store lots of energy
C. Isomers: Compounds that have the same molecular
formula but different structures and hence different
properties
1. C4H10: Differ in covalent arrangement of their C
skeletons
a. Butane:
b. Isobutane:
2. 3 types of Isomers
2
a. Structural Isomers: Differ in the covalent
arrangements of their atoms
b. Geometric isomers: Have same covalent
partnerships but differ in spatial arrangements
1. Vision is initiated by rhodopsin: A
chemical compound in the eye
2. Changing in response to light from one
geometric isomer to another
c. Enantiomers (stereo isomers): Molecules that
are mirror images of each other
1. Left handed and right-handed versions
2. One is biologically active and the other is
inactive
b. Pharmaceuticals: 2 enantiomers of the
same drug may not be equally effective
1. Thalidomide
2. L-dopa and D-dopa
IV. Functional Groups: Groups of atoms that are frequently
attached to C skeletons
A. Regions of organic molecules most commonly involved
in chemical reactions
B. Hydrophilic, increase the solubility of organic compounds
in water
1. Estradiol and testosterone
6 Functional Groups
1. Hydroxyl Group: H is bonded to O which is bonded to
the C skeleton -OH or OH3
a. Alcohols: Organic compounds containing hydroxyl
groups (end in -ol)
2. Carbonyl Group (=CO): C atom joined to an O atom by
a double bond
a. Aldehyde: End of C skeleton
b. Ketone: Not at the end of a C skeleton
3. Carboxyl Group (-COOH): O is double-bonded to C that
is bonded to a hydroxyl group
1. Carboxylic acids: (organic acids)
a. Formic acid:
b. Acetic acid:
2. Source H ions
3. Covalent bond between O and H is so polar that H
dissociates reversibly as an H+
4. Amino Group (-NH2): N bonded to 2 H atoms and to the C
skeleton
1. Amines: Organic compounds with an amino group
a. Glycine: An amino acid
1. Also has a carboxyl group
2. Amine and Carboxylic acid
2. Most of the cell’s organic compounds have 2 or more
different functional groups attached to their C skeleton
3. Acts as a base
a. Can pick up protons from surrounding solutions
b. + charge, common state within the cell
5. Sulfhydryl Group (-SH): S bonded to H
4
1. Resembles a hydroxyl group in shape
2. Thiols: Organic compounds containing sulfhydryls
a. Interact to help stabilize the intricate structure of
many proteins
6. Phosphate Group: Phosphate ion covalently attached by one
of its O to the C skeleton
1. Phosphate:
2. Transfers energy between organic molecules
5