But other transmembrane proteins or integral proteins are basically attached onto physical structures. For instance, in this case, it's attached not only onto the collagen fibers of the extracellular matrix found outside the cell but they're also attached onto the filaments in the cytoskeleton found in the cytoplasm inside of that cell. So this one will be relatively mobile while this protein will be able to move along that lateral direction. Now, what allows these fossilipids to actually move along that direction? Well, basically, as the fossilipid moves along the lateral direction those bonds between the water molecules and the polar heads remain. And likewise, the bonds between the jason hydrocarbon non polar tails also remain.