Question

what is #3 pointing at? 1 2 3 4 5 lipid bilayer peripheral protein glycoprotein

Explanation:

Peripheral proteins are loosely associated with the cell - membrane and are not embedded in the lipid bilayer. In the diagram, the structure pointed at by #3 is attached to the surface of the membrane, which is characteristic of a peripheral protein. Lipid bilayers are the main structural component of the membrane, forming a double - layer of lipids. Glycoproteins have carbohydrate chains attached to them and are usually more complexly integrated into the membrane structure.

Answer:

peripheral protein