# Isomers --- **Isomers** are two [[molecule|molecules]] that have the same [[chemical formulae]], but have a different *arrangement* of the atoms in space. This *does not* include any different arrangements which are simply due to the molecule rotating as a whole, or rotating about particular bonds. A class of [[enzyme|enzymes]] called **isomerases** specilize in converting one molecule to its isomer molecule. - **Structural isomers** are atoms that are arranged in a completely different order. - **Chain isomers** arise because of the possibility of branching in carbon chains. - **Position isomers** have the same basic carbon skeleton, but the important groups are moved around on the skeleton. - **Functional Group Isomers** contain different [[functional group|functional groups]]. - **Optical isomers** are mirror images of one another. They cannot be superimposed. Notible optical isomers are [[amino acids|amino acids]]. ___