Which of the following statements is NOT true? The three types of lipid anchors responsible for tethering proteins to the bilayer are acylation, prenylation, and GTPase anchors. Glycoproteins are always oriented so that the carbohydrate moieties are exoplasmic. Glycoproteins are the basis for blood type compatibility between donor and receiver. Movement of proteins from the cytoplasmic to the exoplasmic face of the lipid bilayer requires specialized transport proteins, often flippases.