Final answer:
The correct answer is B) Transmembrane; peripheral. Transmembrane proteins span the plasma membrane, while peripheral proteins are loosely attached to the membrane's surfaces.
Step-by-step explanation:
The plasma membrane proteins that span the membrane are called transmembrane proteins, whereas proteins that are only partially embedded, in either the cytoplasmic or extracellular side, are called peripheral proteins. Therefore, the correct answer to the question is B) Transmembrane; peripheral. Transmembrane proteins are integral proteins that extend across the membrane, often acting as channels or pumps for substances to move into or out of the cell, and are important for various cellular functions including cell adhesion and cell recognition.
Peripheral proteins, by contrast, are not embedded within the lipid bilayer but are loosely attached to the exterior or interior surfaces of the membrane, either to integral proteins or to the phospholipid molecules. These can serve as enzymes, be involved in cell signaling, or provide structural support.