 Chemistry underlies everything we see around us. Chemistry is the science of atoms, molecules and ions. Hi, my name's Joe and I've just finished my PhD in biomolecular interactions at the Research School of Chemistry at the Australian National University. As chemists, we're really interested in studying the composition, structure and the properties of these molecules and learning how they interact with each other. By doing so, we can better understand the world around us. Chemistry is often called the central science because it links fields like physics with more applied science like medicine. Importantly, understanding chemistry lets us do some pretty exciting things as well. For example, if we want to come up with new materials, things like flexible plastics or flexible materials, we can build things like solar panels out of. We need to understand what's happening down at the level of individual atoms. Similarly, if we want to design better drugs and medicines, we need to be able to understand the types of chemical reactions that we can use to build these molecules and also how they're going to interact with things like protein and DNA when we put them into our own bodies. I'd have to say I didn't really enjoy doing chemistry at high school. It was probably my least favourite subject. It was only really when I got to university that I started to realise how important it was to understand the molecular world. In particular, I became very interested in understanding the chemistry of life, the types of chemical reactions that are occurring within our own bodies, within our own cells. Indeed, our cells are just full of chemical molecules, from things like calcium ions to molecules like dopamine that control our mood and behaviour, to the larger biological molecules like DNA and proteins that control all of life itself. As part of my PhD, I was particularly interested in studying the shape and structure of biological molecules like proteins. In order to do this, we have to have a really good understanding of how atoms interact with each other, because this defines what these protein molecules are doing in our cells. Our research group is particularly interested in understanding the shape and structure of these protein molecules and how they move in the cell. To do this, we use a technique called X-ray crystallography, which lets us build a model of these protein molecules so we can understand what they look like, but we can also understand the ways that we can manipulate them to make them better or more useful. We can create proteins that are better for use in industry, things like breaking down herbicides in waterways, and that's really useful. But to be able to do that, we need to be able to understand the structure of these proteins first, so that's what my research is all about. To be able to study these biological molecules, we need to have a really high level knowledge of the fundamental concepts of chemistry, how atoms interact with each other, and how the different types of chemical reactions are occurring inside the cells. I really enjoy doing this kind of work. I get to work with researchers from all over the world, and I get to work on projects that have some very far-reaching applications. You've already started to learn the fundamentals of chemistry. In the next sections, you'll be learning about these fundamentals in further depth. Why is it that a carbon atom is in some way similar to a silicon atom? What happens to atoms when you add or take away electrons? And how the scientists use this information? After the next sections, you'll be able to answer these questions.