What is osmosis?

Osmosis specifically refers to the process by which water molecules move across a selectively permeable membrane. This movement occurs from an area of lower solute concentration to an area of higher solute concentration, driven by the concentration gradient of solutes. Osmosis is crucial for maintaining cellular homeostasis, as it helps regulate the internal environment of cells by balancing water levels.

In many biological systems, such as in the cells of plants and animals, this process is vital for the proper functioning of cells. Water will move through specialized channels called aquaporins or directly through the cell membrane, allowing the cell to respond to changes in its environment, such as changes in solute concentration in the surrounding fluid. Thus, the essence of osmosis is the passive diffusion of water, which differentiates it from other transport processes like active transport, which requires energy.