semipermeable membrane

A semipermeable membrane is a special type of barrier that allows certain substances to pass through while blocking others. Think of it like a filter: it lets smaller molecules, such as water, pass through easily, but keeps larger molecules, like proteins or salts, from getting through. This property is important in many biological processes, such as how cells regulate what enters and exits. It helps maintain the right balance of nutrients and waste products, ensuring that living organisms can function properly.