Final answer:
The statement is true; oligosaccharides are always on the noncytosolic (extracellular) side of the cell membrane due to the orientation established in the ER and Golgi apparatus.
Step-by-step explanation:
The statement in question, “true or false the oligosaccharides are always on the noncytosolic side of the membrane,” is true. Oligosaccharides are carbohydrates that consist of a small number of monosaccharides (sugars). In the context of a cell membrane, these oligosaccharides are typically found on the extracellular side of the plasma membrane, where they are involved in cell recognition and signaling. This is due to the way proteins are processed in the endoplasmic reticulum (ER) and Golgi apparatus. When proteins are synthesized in the ER, they are often glycosylated, which means sugar chains (oligosaccharides) are added. As these glycoproteins move through the Golgi apparatus, they are further modified and then directed to the plasma membrane with the sugar side facing outwards.
If a peripheral membrane protein were synthesized inside the lumen of the ER, it is destined to become a part of the plasma membrane, facing the extracellular space, thus ending up on the outside of the plasma membrane, consistent with the orientation of oligosaccharides.