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ORGANIC CHEM! HELL YEAH.
Study sheet(s). Or guide.
Organic chem concerns molecules with carbon.
The chem side of organic chem is really like learning a new language. You have loads
of stuff to memorize and familiarize yourself with, but once you have the building
blocks you can mix and match and then feel good about achieving a lot with relatively
little.
PREFIXES
Here is a list of prefixes you will come across regularly in organic chem. Its best you
have them memorized as early as possible, since you will be using them a lot. Don’t
worry if you have no idea what they mean; it will become clear later on.
Number 1
Prefix
2
Meth- Eth-
3
4
Prop- But-
5
6
7
8
Pent-
Hex-
Hept- Oct-
9
10…
Non-
Dec-
It’s useful to realize that only the first four are different from your normal
Greek/Latin prefix; the rest should be familiar. (Please blame methanol, ether,
propionic acid and butyric acid; the first four prefixes were named after them,
respectively).
Prefixes of 11 and higher are much less common, and can be found on Wikipedia
easily if you happen to come across them.
ALKANES
This is the simplest class of organic molecules; they contain only carbon and
hydrogen atoms, with all single bonds and NO cyclic structures (this will be discussed
later).
The general form of alkanes is:
As a result the general formula for alkanes is
CnH2n+2. (Pattern recognition
anyone? Oh the joy of MYP mathematics)
In order to name alkanes, you count the number of carbons you have in the chain, find
the corresponding prefix, and add the suffix “-anes”.
FOR EXAMPLE:
This has ONE carbon. The prefix for one is “meth-”.
Therefore this molecule is “methane”.
This has TWO carbons. The prefix for two is “eth-“.
Therefore this molecule is “ethane”.
This has THREE carbons. The prefix for three is “prop-“.
Therefore this molecule is “propane”.
You get the idea.
ALKENES
These molecules are also made up of carbons and hydrogens, but contain at least one
double bond in the carbon atoms. Just like for the alkanes, we name the alkenes by
counting the number of carbons in their chain, finding the corresponding prefix, and
adding the suffix “-ene”.
This has TWO carbons. The prefix for two is
“eth-”. Thus this molecule is named “ethene”.
This has THREE carbons. The prefix for three is
“prop-“. Thus this molecule is named “propene”.
Things get a little trickier when we have at least four carbon atoms in the chain. This
is because there are different possibilities as to where the double bond can appear in
the chain. For example, an alkene with four carbon atoms in its chain could be:
OR
In order to encode where the double bond is in the carbon chain, we number the
carbons in order (left to right or right to left is irrelevant as you shall see), and put this
number “n” into but-“n”-ene.
The double bond starts on carbon
number 1. This is therefore but-1-ene.
Note that the double bond also starts
on carbon number 2, but it is NOT
but-2-ene; the convention is we
number the carbons such that the
resulting name has the lowest numbers
possible.
The double bond starts on carbon
number 2. This is therefore but-2-ene.
Note that it is NOT but-3-ene.
In a similar way, if you have more than one double bond, you simply list out the
carbon numbers, and change your suffix into “diene” or “triene” etc, corresponding to
the number of double bonds.
Eg C=C-C=C is written as but-1,3-diene.
C-C=C=C=C is written as pent-1,2,3-triene.
C=C=C=C-C=C is written as hex-1,2,3,5-tetrene.
(the hydrogens here are omitted)
ALKYNES
This is the final class of linear molecules composed of carbon and hydrogen. It
contains triple bonds. Alkynes are named in exactly the same way as alkenes; you
have to take into account when the triple bond starts. The suffix for triple bonds are
“-yne”
Eg H-C≡C-H is written as ethyne.
C≡C-C is written as propyne.
C≡C≡C is written as prop-1,2-diyne.
C≡C-C≡C is written as but-1,3-diyne.
C≡C-C≡C≡C is written as but-1,2,4-triyne.
FUNCTIONAL GROUPS
Organic molecules are given different characteristics based on their functional groups.
These are special components or parts of the molecule
Name
Hydroxyl
Carboxyl (the
defining group
in alcohols)
Amino
Phosphate
Sulfhydryl
Aldehyde
Ketone
Structure
Non-ionized
Ionized
Now for the BIOLOGICAL side of organic chem.
READ THIS!!!!!!!!!!!!!!!!!!!!!!!!1111111ONE
http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%20101
%20lectures/biochemistry/biochemi.htm
(you might notice that the previous table regarding functional groups was taken from
this link. Gasp.)
Pay special attention to the parts regarding carbohydrates, lipids and amino acids.