🧪🔬🔍 A membrane is a thin, flexible barrier or sheet that separates and encloses different compartments or substances. It acts as a selective boundary, allowing certain molecules or ions to pass through while restricting the movement of others. Membranes are essential in various biological processes, such as cell communication, transport of nutrients, and maintaining cellular integrity. They are extensively studied using scientific tools like laboratory experiments, microscopes, and careful analysis to uncover their structure, composition, and functions at a microscopic level.