<prompt> The cell membrane consists of various components, including integral proteins. These integral proteinsAre not attached to the outer leafletAre not attached to the inner leafletInclude transmembrane proteinsAre preferentially attached to the surface  <response>: The membrane proteins are classified into two categories: Integral proteins or intrinsic membrane proteins Peripheral proteins or extrinsic membrane proteins. Integral proteins are not only closely associated with the lipid bilayer but also tightly bound to the cell membrane. 