Final answer:
According to the fluid mosaic model of the cell membrane structure, proteins are mostly involved in Transport.
Step-by-step explanation:
According to the fluid mosaic model of the cell membrane structure, proteins are mostly involved in Transport. The fluid mosaic model proposes that integral membrane proteins are embedded in the phospholipid bilayer of the cell membrane. Some of these proteins span the entire membrane and act as transport proteins, facilitating the movement of molecules and ions across the membrane. These proteins serve as channels or pumps, allowing specific substances to enter or exit the cell.