Sugar Sugar or Sugar raguS ??

I was talking with my friend Techy Tim yesterday. He called me to ask about the structure of cellulose. What a good idea for a Blog I thought

Don't be put off, I think you will find it interesting, especially when we get to the bit about potatoes?

There are many different types of sugar, the white crystals that we heap into our tea and coffee is a sugar called sucrose.Honey is sweet because it contains two different sugars, sucrose, and fructose. Another interesting sugar is maltose. Does that word sound a bit familiar? Malt whiskey, malted milk, malty tasting beer? Maltose is a type of sugar produced during the fermentation of grail to make those nice alcoholic products we like to drink. I guess its been a long time since any of us tasted breast milk. If we could remember, we would find that it was sweet, that's one reason babies are attracted to it. The sweetness is due to a sugar called lactose, hence the term lactating mothers.

But what has all this got to do with papermaking? Well, there is one important sugar I have not mentioned yet. GLUCOSE. Glucose is in all the energy drinks, it is the sugar that the body converts into energy. It is also the basic building block in all plants.

All plants, from the humble snowdrop to the giant redwood trees use the same process. They take in chemicals from the air and the soil, and they convert them into millions of little glucose molecules. Its rather like a brick factory producing millions of identical bricks. The only difference is that each end of a brick is the same, with glucose molecules, each end is slightly different.

So a plant is rather like two factories, one factory, as I have said, makes the glucose molecules. The other factory sticks them all together to make long thin chains, or sometimes branched chains.

If the assembly line puts all these glucose molecules together in the same way, like this

-SUGAR-SUGAR-SUGAR-SUGAR-

We get, what we call starch. Starch is the energy store of the plant. A potato is a good example of a plants energy store. I will return to the potato later.

If the plant assembles the glucose molecules in a different way, like this:

-SUGAR-RAGUS-SUGAR-RAGUS- 

Then the material it produces behaves in a very different way, this is what we call cellulose. This is the structural part of the plants, the leaves and stems and trunks of trees for example.

In the starch example there is a R-S 'bond' that joins up all the individual glucose molecules. The enzymes in our bodies can break that bond, releasing the individual sugar molecules that our body can then convert to energy.

In the cellulose chains the joining groups are different, half are R-R and half are S-S. Our body cannot break them, so they pass right through us. This is what we call fibre, and this is what helps the poo slide through!

Thios is also what makes the individual fibres that make paper!