Biopolymers: Chains for life

A preface to the biopolymers series

In order to fully understand the subsequent entries of these series in the blog, first of all I should explain what biopolymers, and more generally speaking, polymers are. But hide that knife, I’ll try not to go deeper (and more academic) than needed since, probably, some of you know them very well , and other don’t really want to become experts on the matter. Anyway, if you are familiar with polymeric affairs, maybe you would want to skip this post.

 

Styrene.png
Styrene molecule

Polymers are large or very large molecules composed of repetitive units of smaller size called monomers. Like in a chain, the small links are connected to each other, sometimes thousands or millions of them, but being able to form branches and crosses. Each of this monomers can be also stared as molecules on their own when they are free, with some differences due to the uncoordinated state.

Polystyrene.png
Polystyrene. Combination of styrene molecules

So, long story short: it’s a very big molecule made of other smaller “molecules”.
Bio stands for biological. That was easy, wasn’t it. And why should I worry about this? What’s the point of it? Why are you doing this to me?!. Well, because you are made of biopolymers! Structural proteins like collagen in your skin, muscles and bones, or keratin in your hair or nails are biopolymers. In fact, all proteins like hormones and enzymes are. But also, what defines what you are biologically speaking: your DNA is a biopolymer. The small molecules that constitute the polymeric proteins are called amino acids, and the ones in your DNA, nucleic acids. I’m pretty sure you heard those names before.

 

chitin structure
Chitin. A biopolymer widely produced by nature

There is also another large group of biopolymers, but made from sugars in this case. Sugars are a wide family of organic compounds/molecules, so try not to think too much about the white powder we all know, which is called sucrose and is formed by one molecule of glucose and one of fructose.

Starch is a better example: it’s also made of glucose, same monomer, but the chains are way longer. Glucose comes from the Greek word for sweet (random fact).
Again, don’t get a wrong idea about this compounds, because not everything is so sweet as the starch. Chitin, the structural polymer in insects’ carapaces, is also made from a “sugar” (monosaccharide is a much more accurate therm); that one called N-Acetylglucosamine.
Of course polymers’ properties are very different from those of the molecules from which they are composed. Even though monosaccharides tend to be sweet, please, don’t lick a bug and then mail incriminating me of deceiving you.

As you can see, biopolymers are essential elements in life as we know it. But not because of random reasons. They made very good materials. Also we can use their unusual properties in our convenience. In the next entries, we will talk about the spider web and its awesome resistance, and also about shrimps carapaces and wound healing (yes, wound healing), and much more. Stay tunned!

 

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