Answer:
Due to the semi-permeability of cell membrane, the molecules that allow large molecules to cross the membrane are proteins, specifically membrane integral proteins.
Step-by-step explanation:
Membrane integral proteins are protein molecules that are part of the cell membrane, pass through it and cannot be separated from it. These molecules allow the passage of polar molecules and large molecules.
The channels and transporters are structures formed by integral proteins, which facilitate the passive and active transport of macromolecules, respectively.
The cell membrane is a lipid bilayer whose hydrophobic nature allows the passage of some substances and prevents the passage of others, which can pass through the membrane by using channels and protein transporters.