Chitin: The Marvelous Molecule
By Trish Weaver
Last November I co-authored a paper on organic material consistent with chitin found in the cuttlebones of an approximately 34 million year old (Late Eocene) cuttlefish (http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0028195). Since then, I’ve been thinking a lot about chitin and how it really is a marvelous molecule. Not only can it be preserved in a recognizable state for 34million years, chitin signatures have been recorded as far back as the Silurian.
So just what is chitin? Chitin is a nitrogen-rich polysaccharide, N-acetyl-glucosamine to be exact. Great, Trish, that clears things up. Basically chitin is a protein-linked sugar. Sound tasty? Not really. Chitin is the stuff that makes up crab shells, beetle carapaces and is the stuff that goes crunch when your calamari isn’t cleaned well. Chitin is found in most invertebrates, some fungi and some algae. It’s the second most abundant biomolecule found in nature.
Yeah, cellulose is number one…stupid plants. Unfortunately, as humans we don’t produce chitin, though wouldn’t it be cool if we could? Imagine being able to grow a hard exoskeleton to protect us from life’s cuts and scrapes. Franz Kafka may have had it right with that whole metamorphosis thing. We may not be able to produce our own chitin, but we can take advantage of it. We can use the nitrogen released from decomposing chitin to fertilize our crops. If our joints ache, we can take glucosamine tablets (yes, they’re basically just powdered shrimp shells) and if we need dental implant surgery, we can use chitin strips to help promote bone growth.
Want to impress your friends with your scientific knowledge? Next time you see a butterfly, explain that butterfly wings are made of sheets of chitin or gross your friends out by telling them that slugs have rows of rasping teeth called radula… made of… you guessed it…chitin. Now that’s a marvelous molecule! Chitin can even help support the soft tissues in a giant or colossal squid, but that’s another story…