Antioxidants: come along for a little chemistry

Let's look at antioxidants and a bit of chemistry.

I realize there are many folks out there who would rather eat dirt than deal with the subject of chemistry, but it is interesting!

I hope you remember the page I published a while back. You know, the page about the additives commonly found in beauty soaps. That wasn't bad, was it?

I had explained that my success as chemistry tutor in the good old days was largely based on presenting the material in a fun way, showing its practical applications.

Well, I tried... Yet for some, no matter what I said or demonstrated, chemistry was still viwed as a complicated, dreadful, mysterious and boring arena.

I apologize, but we really do have to brush up on some terms here. I'll do my very best to keep everything as simple as possible. To all the chemistry fans out there, please don't start splitting hairs!

All right, definitions time.

Antioxidants are molecules that slow down the oxidation of other chemicals. Low quantities of these important molecules may be responsible for oxidative stresses that can kill cells.

Oxidative stress is due to an imbalance between a system's ability to detoxify certain substances and the production of a reactive oxygen.

Recently, much research has been carried out in an effort to understand the link between oxidative stress and human illnesses such as neurodegenerative diseases (including strokes).

Some of the best known antioxidants include vitamin E, vitamin C, and glutathione, a tripeptide which is found in most types of aerobic life.

Some more difinitions:

Tripeptides are made up of three amino acids that are linked by peptide bonds.

Peptides are short molecules that are formed by a specific linking of amino acids.

Peptide bonds are chemical bonds that are formed between two molecules whenever the carboxyl group of one reacts with the amino group of the other, and a molecule of water is released.

Don't worry, I will not go into a discussion of amino acids, superoxide dismutase, enzyme systems, carboxyl groups, etc.

If someone wants to know about them, just tell them, "They're important stuff...", and say so using your best reverent tone, just to impress them - you hope!

Antioxidants are usually categorized under two divisions:

- hydrophobic (soluble in lipids);

- hydrophilic (soluble in water).

The hydrophobics protect the membranes of cells from peroxidation (another "important stuff" character...)

The hydrophilics do their work in blood plasma and in the cytoplasm of cells.

Antioxidants can be found in fruits, nuts, legumes, vegetables, and grains. The amount varies among foods. For example, bananas do not have as many as broccoli.

Before I finish, I'd like to give you another "heads up" about the very popular ascorbic acid (vitamin C) and lycopene (tomatoes are rich in lycopene).

If you feel you must supplement you diet with these two substances, pay close attention to the manufacture date and expiry date. Ascorbic acid and lycopene are easily destroyed by long-term storage. Another excellent reason why you should start growing tomatoes!

Thank you for your patience with this chemistry class.

Antioxidants and organic claims