CARBON AND THE MOLECULAR
DIVERSITY OF LIFE
Chapter 4
How well do you know the carbon atom?
• Number of protons ______
• Number of neutrons ______
• Number of electrons ______
• Atomic Number ______
• Atomic Mass ______
• Valence Electrons ______
• Electrons needed to fill valence shell ______
• Type of bond carbon atoms readily form ____________
Valences of the major elements of organic
molecules
• Hydrogen ______
• Oxygen ______
• Nitrogen ______
Structural formula for CO2 and CO(NH2)2
Carbon Dioxide
Urea
Naming Hydrocarbons:
__________
__________
__________
__________
__________
__________
II. Hydrocarbons: naming conventions
Roots/Prefixes (2C stands for two carbons)
1 C - ____meth__
2 C - ____eth____
3 C - ____prop___
4 C - ____but____
5 C - ____pent____
Butane
Butane
6 C - ____hex____
7 C - ____hept___
8 C - ____oct____
9 C - ____non____
10 C - ___dec____
Butane
Hydrocarbon Naming Conventions, Formulas and Examples
Series of
Hydrocarbon
-ending
Formula to determine #
of H atoms *
Bonding
Alkane
ANE
Cn H2n+2
Single Bonds Only
Alkene
ENE
Cn H2n
One Double Bond
C
Alkyne
YNE
Cn H2n-2
One Triple Bond
C
*
Where “n” is the number of carbon atoms
C
C
Hydrocarbons:
Name the molecule:
C6H12O6
Isomers:
• Compounds with the same molecular formula but different
structures and properties.
Isomers:
Structural Isomers:
• Have different covalent arrangements of their atoms
Geometric Isomers:
• Have the same covalent arrangements but differ in spatial
arrangements
Enantiomers:
• Isomers that are mirror images of each other
• The middle carbon is called an asymmetric carbon
because it is attached to four different atoms or groups of
atoms
How many asymmetric carbons are in this
molecule?
a
b
c
d
e
ONE!!!
Enantiomers:
• Enantiomers are important in the pharmaceutical industry
• Two enantiomers of a drug may have different effects
• Differing effects of enantiomers demonstrate that
organisms are sensitive to even subtle variations in
molecules
Enantiomers:
Functional Groups:
• Functional groups are the components of organic
molecules that are most commonly involved in chemical
reactions
• The number and arrangement of functional groups give
each molecule its unique properties
Functional Groups:
• The seven functional groups that are most important in
the chemistry of life:
• Hydroxyl group
• Carbonyl group
• Carboxyl group
• Amino group
• Sulfhydryl group
• Phosphate group
• Methyl group
Hydroxyl:
What it looks Like…
What it Makes……
alcohol
Example(s):
Functional Properties:
 Is polar
 Can form hydrogen bonds
with water molecules
Carbonyl:
What it looks Like…
What it Makes……
Aldehyde – end
Ketone - middle
Example(s):
Functional Properties:
 A ketone and aldehyde
may be structural isomers
 These two groups are
found in sugars giving rise
to two major types of
sugars
Carboxyl:
What it looks Like…
What it Makes……
Carboxylic Acid
Example(s):
Functional Properties:
 Has acidic properties (is a
source of hydrogen ions)
because the covalent
bond between the oxygen
and hydrogen is so polar
Amino:
What it looks Like…
What it Makes……
Amine
Example(s):
Functional Properties:
 Acts as a base; can pick
up an H+ from the
surrounding solution
 Ionized, with a charge of
1+, under cellular
conditions
Sulfhydryl:
What it looks Like…
What it Makes……
Thiol
Example(s):
Functional Properties:
 Two sulfhydryl groups can
react forming a covalent
bond. This “crosslinkage” helps stabilize
protein structure.
Phosphate:
What it looks Like…
What it Makes……
Organic Phosphate
Example(s):
Functional Properties:
 Has the potential to react
with water, releasing
energy
Methyl:
What it looks Like…
What it Makes……
Methylated Compounds
Example(s):
Functional Properties:
 Addition of a methyl group
to DNA, or to molecules
bound to DNA, affects
expression of genes.