Partially Permeable Membrane - GCSE Biology Definition

A partially permeable membrane is a thin barrier that allows certain small molecules to pass through it while blocking others. In biology, it is important for processes like osmosis, where water moves across the membrane from a region of low solute concentration to a region of high solute concentration. These membranes are found in living cells and help control what enters and leaves, such as nutrients, water, and waste. This selective passage is crucial for maintaining the right conditions for cell function and health.