Protein Structure 1

Since every author on this page is studying biomolecular science of some fashion, you’re going to run into this word eventually, so sit back and enjoy….

Derived from the Greek word “prtos” meaning “first”, proteins are much more than simply stuff that makes a steak. In fact proteins are hugely variable molecules involved in sight, digestion, growth and pretty much any process in the body you care to name.
Despite their impressive list of achievements and boastful name, proteins are themselves formed from smaller building blocks called amino acids.

Like the combination of 4 bases leads to the diversity of our genome, the combination of 20 different types of amino acid into linear chains leads toASS amino acid the huge diversity of proteins possible in our cells.

This is because all 20 amino acids have different properties, whether they are charged (positively or negatively), insoluble in water, or contain chemical groups capable of reacting with other compounds. And yet, rather annoyingly, I have to tell you that they are all also very similar as figure 2 illustrates:

ASS amino acid 2

As you may have noticed the molecule in blue is identical to the one in red. However this is because, while all other letters signify elements (carbon, nitrogen and hydrogen), the “R” represents a variable group or “side chain” that sticks out from the main chain – much like the blue “atom” in figure 1, and this can be any one of the 20 different side chains on amino acids that make them unique.

Therefore the sequence of amino acids in a protein – called its primary structure – determine what properties certain regions of a protein will have (such as a positively charged cluster). The types of amino acid incorporated into the chain also determine the secondary structure of the protein, this is how the chain folds and interacts with itself to start to form a 3D structure, expect more of this in my next protein adventure.

But for now, remember:

  •         The length of amino acid chains varies hugely within the forms of protein. The largest, Titin, is 30,000   amino acids long – making them hugely variable
  •         Proteins are formed from combinations of 20 types of building blocks called amino acids >
  •         The sequence of amino acids, called “primary structure” largely determine a proteins properties

If this was either too vague or totally enthralling, then check in at a later date for more,

Class dismissed.

photo credit: <a href=”http://www.flickr.com/photos/widdowquinn/5261696750/”>widdowquinn</a&gt; via <a href=”http://photopin.com”>photopin</a&gt; <a href=”http://creativecommons.org/licenses/by-nc-sa/2.0/”>cc</a&gt;

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