Membrane transport proteins are essential for life. They transport essential nutrients and minerals across the membrane barrier that surrounds each cell in the human body. This transport is necessary for every living process – from eating and breathing to learning and doing daily work. Those proteins are important for central nervous system including brain and other nervous cells to work appropriately. The human body has a lot of different types of these kinds of membrane proteins; each can move different things. The “CLC” type moves an anion called chloride, which we can get from our daily diet. One CLC type protein, CLC-2, is important for brain and other nervous cells to sense the signal and lead the body to do an appropriate response. My goal is to take “pictures” of this proteins using a method called cryo-electron microscopy. By taking pictures under different conditions, I will determine how this protein change shape to do their job of moving things across the cell membrane barriers. These results will help us to know how these protein work in our nervous system and in the whole body.