We've decided to adopt, just as a loose theme for the course, a biological theme so that you can see the connections between chemistry and biology and the things that you might consider doing in the future. We want you to think about the molecules that are relevant to your body, the processes that occur in your body, the chemistry that's going on and how energy plays a role. And we divided the course into four sections and after each section there will be a mid-term. The first one, or an exam. The first one is about matter.