Organic & Biomolecules


The molecules that make up the organic and biomolecules category are a special of covalently bonded substances. Also known as hydrocarbons, these molecules are or were part of living organisms. Almost all organic and biomolecules have the element carbon as their main structural component. These chains of carbon can be one, tens hundreds or even thousands of carbons long. Each chain can have dozens of functional and/or additional groups attached to them. The prefixes used for the organic and biomolecules are slightly different than the other prefixes used for standard covalent molecules and are listed below.


Organic and Biomolecules Prefixes


1 meth

2 eth

3 prop

4 but

5 pent

6 hex

7 hept

8 oct

9 non

10 dec


There are several classes of organic and biomolecules listed below. Each of the classes are identified by a functional group that makes them unique. When naming organic molecules it is important to identify where the functional group is by numbering the carbon chain so that the functional group is on the lowest numbered carbon. Often the Lewis Dot Diagram is more helpful to look at than the formula. To simplify the Lewis Dot Diagram the hydrogens are generally left out of the picture and are understood to be there. Often the generic carbon chain is symbolized by the letter R (i.e. R-OH is an alcohol since OH is the alcohol functional group). This means that the R can be any carbon chain of any length with any side chains.


Alkanes, Alkenes & Alkynes


Alcohols & Carboxylic Acids


Ethers & Esters


Aldehydes & Ketones


Amines & Amides




Side Chains








Nucleic Acids