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You probably think you know about sugar- it’s the white stuff you put in your tea, right? But that’s just one kind of sugar (called sucrose), and the chemistry of sugars can be very complex! You’ve probably heard of some other types of sugar before – glucose (found in lucozade) fructose (from fruit) and lactose (from milk). These sugars are quite simple, and we call them monosaccharides and disaccharides. You can check out http://www.chem4kids.com/wp-content/uploads/sites/1/files/bio_carbos.html for more info about the different types of sugar.

But when we look at the sugars in your body, things start to get a bit more complex. My work deals with a polysaccharide called heparan sulfate. Polysaccharide means this sugar is made up of thousands of sugar units, making the sugar really complex. Heparan sulfate is interesting to scientists because it plays an important part in sending messages in your body. So if a cell in your body wants to grow, it needs heparan sulfate to interact with a protein to set this process going. But heparan sulfate is also involved when a cell becomes cancerous- this growth signal increases causing the cancer to grow quickly. Heparan sulfate is also involved when the HIV virus enters a human cell.

We hope to investigate the interactions between heparan sulfate and proteins to work out how we could block them and stop cancer growing so fast or stop HIV entering a cell. To do this, we have to make simpler sugars which are like heparan sulfate as it’s too complex to study. This is part of the bigger field of synthetic organic chemistry, where scientists make complex molecules from simple ones. We then want to use fluorescence (a process where chemicals absorb and re emit light, like in a glow stick) to study the interaction of the sugars we made with proteins from humans. Hopefully our findings will help us discover a sugar that can be used as a new medicine!

I usually start the day in the lab by setting up a chemical reaction. Before doing this, I need to work out what chemicals to use and in what amounts- usually chemists do this by looking at what other chemists have done before and tweaking it a bit. The work of scientists is published in scientific journals (fancy magazines!) so we can all read it.

I do all my reactions in something called a fume cupboard, as most chemicals in our lab are bad for your health if you breathe them in. The fume cupboard draws the air inside away so you don’t breathe it in. I also wear gloves, safety glasses and a lab coat. Here’s my fume cupboard in my lab

Putting on the reaction doesn’t normally take that long, but chemical reactions can take from 1 hour to 1 week to complete so sometimes I have a wait! The reaction doesn’t look like much when it’s going- just some liquid (called the solvent- see http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/chemical

/detergentsrev3.shtml to find out more) with some chemicals in. Here’s some I put on yesterday

When the reaction works it might change colour if you’re lucky, but most of the time it doesn’t! I use a technique called Thin Layer Chromatography (TLC) to see if the reaction has worked or if it needs more time. You just put a little bit of the reaction mix on a special sheet and let solvent run up it, and this makes the chemicals separate out. Something happened in this reaction- new chemicals have formed shown by the new spots in the right hand column

You can find out more about TLC at http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/

covalent_compounds/seperationrev2.shtml

If the reaction’s done the hard work then starts! It needs to be purified- all the other chemicals need to be taken out to give me just the product I need. Column chromatography can be used for this- it’s the same as TLC but bigger! Here’s a picture of the column used

Most chemists hate these because they take a couple of hours to do!

In the time I’m not in the lab, I type up the lab work I’ve been doing to be used in my final PhD report in a few years time, I go on training courses, read about other scientists’ work and tell people about my own work too!