The Molecular Universe

Emo-Molecules

The molecule below is enkephalin. It is a peptide, that is, it is composed of amino acids, connected together by peptide bonds. Protein molecules are formed in precisely the same way. Peptides are smaller molecules than proteins and are often used in signalling within our bodies.

Enkephalin is the molecule which is believed to make you feel good when you have exercised or reached an objective. It interacts with the same receptors as morphine and heroin. The next time you are on an emotional high, having just scored a basket, point, goal, or touchdown, enkephalin is the molecule responsible for your sense of well being.

If you compare the enkephalin structure with the structure of heroin you will see that there are similarities. Both molecules possess aromatic ring structures, hydroxyl groups and positively charged regions. Similar structural feature lead to similar behaviors. Of course, the natural enkephalin molecule leads to a short lived natural euphoria, which our minds can cope with. Heroin on the other hand, which is a more robust and less flexible molecule, leads to intense feelings of pleasure and terrible addiction.