Plasma Membrane and Proteins -Proteins within are not rigid and can move around. -In some cases, certain ligands or molecules can bind to a specific receptor and complex of other protein will form. This structure will cause a signal to be transduced to form channels so that molecules can move in. -Plasma membrane proteins: peripheral proteins are connected to the exterior of the membrane. Integral proteins are embedded in the membrane. Transmembrane proteins span the plasma membrane (across). -Six types of Integral Membrane Proteins:Do not focus on memorizing them. Know that one end of an integral protein has an amine group, and the other has a carboxyl group. If the protein is running through the lipid bilayer, the amino acids within that specific protein molecule must be non-polar, hydrophobic.