semipermeábilis

Semipermeábilis is a term used to describe a membrane or barrier that allows certain molecules or ions to pass through it by diffusion, and occasionally specialized facilitated diffusion, while blocking others. The rate of passage depends on pressure, concentration, and temperature of the molecules or substances traversing the membrane, as well as the permeability of the membrane to each substance.

This property is fundamental in many biological and chemical systems. In biology, cell membranes are a prime example of semipermeable membranes. They regulate the passage of substances into and out of cells, maintaining cellular integrity and function. For instance, water can pass freely across cell membranes through osmosis, while larger molecules like proteins and complex carbohydrates are generally prevented from entering.

In chemistry and industry, semipermeable membranes are utilized in processes like reverse osmosis, where pressure is applied to force solvent molecules through the membrane, leaving solutes behind. Dialysis is another application, used to remove waste products from blood by exploiting the difference in permeability of the membrane to various substances. The effectiveness of a semipermeable membrane is often measured by its selectivity and flux.