Osmosis specifically refers to the diffusion of what substance?

Osmosis specifically refers to the diffusion of water across a selectively permeable membrane. This process occurs when water molecules move from an area of lower solute concentration to an area of higher solute concentration, effectively equalizing the concentration of solutes on either side of the membrane. Osmosis is crucial for maintaining cellular homeostasis and function, as cells must regulate their internal environment to ensure that biological processes proceed efficiently.

While solids, oxygen, and carbon dioxide can diffuse, they do not fall under the specific definition of osmosis. Instead, they involve different types of transport processes that do not focus exclusively on water movement or the unique characteristics of water as a solvent in biological systems. Understanding that osmosis is solely concerned with water helps clarify its importance in biological contexts, such as nutrient absorption and waste removal in cells.