But in the case of peripheral proteins, which only interact via these polar regions, by changing the PH or by adding some type of salt solution, we actually disrupt those bonds and that can cause a dissociation of that particular protein. So, two major types of proteins. Now, we'll focus on this in much more detail in a future lecture. But let's discuss integral proteins, and let's take a look at three specific examples that we have studied extensively. So let's discuss bacteria, porin and prostaglandin h two, synthase one. And let's begin with bacteria.