We have an outer mitochondrial membrane and the inner mitochondrial membrane. And this electron transport chain is found on the inner mitochondrial membrane that consists this folding pattern known as Christie that we're going to focus on in just a moment. So let's zoom in on a small section of the inner mitochondrial membrane, this is what we're going to find. So this is the matrix, this portion, and this is the intermembrane space, this space between the inner membrane and the outer membrane. So the outer membrane is somewhere right here. So, as we can see from the diagram, our electron transport chain is located on the inner mitochondrial membrane and it consists of these special types of proteins as we'll discuss in a future lecture.