Osmosis, the movement of water molecules across a selectively permeable membrane, does not require transport proteins. It is a passive process driven by the concentration gradient of water. Water moves from an area of low solute concentration to an area of high solute concentration until equilibrium is reached.
However, while osmosis itself does not require transport proteins, the movement of water can be facilitated by aquaporins, which are specialized water channels in cell membranes. These proteins increase the rate of water transport, but they are not strictly necessary for osmosis to occur. In the absence of aquaporins, water will still diffuse through the lipid bilayer of the membrane, although at a slower rate.
In conclusion, osmosis can occur without the need for transport proteins, but they can enhance the process under certain conditions.