Question

Basis on the fluid mosaic model of the cell membrane, which type of molecule can move passively across the membrane, without the aid of proteins

Answer 1

The cell membrane is composed of a phospholipid bilayer. Because it is made of lipids, they are non-polar molecules. That means that other non-polar molecules can easily pass through. In addition to other non-polar molecules, small, uncharged molecules like water, glycerol, ethanol can also pass through without the use of channel or carrier proteins.   <span />