digibutter.nerr

[Zelnor]

So I decided to start this little series as my intellectual contribution to digibutter.nerr.biz instead of posting picture of cats, repeating video game quotes or saying "ololololololololololol".

Aside from my bashing of trends that tick me off, welcome to "For SCIENCE !"

Episode 1 : Blowing up sugar


The human body is a machine. An incredible amount of specialised microsystems working together, "with the sort of whirring precision you don't notice until it's gone" (Pratchett, Terry - Reaper Man, HarperTorch).
Every cluster of cells that builds an organ has a special task. Every organelle in those cells a certain function. And it all goes hand in hand with an astonishing precision - I as a spiritual person drew some sort of faith from the fact that the human body works at all. DNA - an incredibly complex array or amino acids, carbohydrates and a doublehelix structure - can copy itself. Think about it: a molecule. A highly complex one, but nevertheless a molecule, that outside of the body simply rots. It copies itself. Millions of times a day. With only the most minor of errors - and it can even repair some. And that is only a molecule. Without sentience or consciousness - copying itself over chemical processes, the equivalent of building a spaceship out of rocks and seaweed.

However, enough of that.
People live, day in day out - but, as the machines that our bodies are, we require fuel. We call it "food" and as out cars can only take certain types of gasoline, we need to watch out to get the right diet. Foods can be categorized into the following categories:

Lipid, or fats, which we break down and use as a long-term energy storage, metabolical water source (Fats can be broken down into glucose and water with the right enzyme, more on that later) and to build cell membranes.

Carbohydrates, which are short-term energy sources.

Proteins, the building blocks of our bodies, and emergency iron ration (look at people suffering from anorexia - their body will eat itself in order to survive, causing sometimes irreparable damage.)

And Vitamins, Trace elements, all that stuff the body cannot synthesize itself but instead has to get from outside. Many trace elements would be outright toxic when taken in high dosages, but are nevertheless required.

Any foods we eat are broken down in out digestive systems by acids and enzymes in order to reduce them to their component molecules, which are then pasted together again to build things, nourish things, or be stored as energy. Our body is amazingly versatile - anything unused at the moment will be stored first as glucose (in the liver, it can be modified into Glycogen, which the muscles use as quick energy, or be made into ATP [Adenoside-Tri-Phosphate], the body's super-fuel ) and then later as fat. Fat people carry that extra weight because they ate much more then they needed - and in response to ancient instincts, their body saved for bad times which didn't come.

However, the awesome thing here are enzymes.

Enzymes are macro-proteins that have a catalytic function in the body.
That technobabble means that they change millions upon millions of molecules without changing themselves.
The present understanding of enzymes is the "lock-and-key" principle - enzymes have an active site, a place where a molecule docks onto the enzyme. If all components are ready, the enzyme splits the molecule into its components and then dose the same thing again.

And, since chemical reactions are nothing more then the exchange of electrons and any associated fizzing, bubbling, etc. is only a side-effect of that and the reaction's products, the reactions take place at the speed of light.

And enzymes are IMPORTANT. Without enzymes ? People would spontaneously combust.

We doubted that, but if we were to try metabolizing sugar over sheer temperature, we'd be in the hundreds - way too hot for our water-based cell structure. And you wouldn't believe how much energy is in sugar.

Our chem teacher showed us. He mixed a tablespoon of powdered sugar with potassium chloride and three drops of a catalyst, and... WHOOMPH ! Big purple flame, smoke, and the whole classroom smells of cotton candy. >:

Here the same thing:
http://www.angelo.edu/faculty/kboudrea/demos/instant_fire/instant_fire.htm

In this case, the sugar is the original substance - the substrate - and then potassium chloride and hydrochloric acid are the enzyme (technically the potassium chloride doesn't count as it only releases lots of oxygen for the sugar to oxidize, but I may be wrong.)

So if we didn't have enzymes, a tablespoon of sugar could make us go "parp". Which would be a lot less fun then we'd think


I'm Zelnor, and you were reading "For SCIENCE !"

Tune in some time later to learn more from IB Chemistry. Only here, at digiblogger.

P.S. :

A) Suggested further material:
http://en.wikipedia.org/wiki/Enzyme
http://en.wikipedia.org/wiki/Adenosine_triphosphate
http://en.wikipedia.org/wiki/Glycogen