Every cell is surrounded by a living boundary—a biological membrane that controls what enters and leaves. In this episode of Deep Dive, we explore the structure and function of cell membranes, uncovering how the phospholipid bilayer and embedded proteins create a dynamic, selective barrier. 🔬💧 Learn how membranes enable communication, transport, and energy conversion, and why their fluid nature is vital for life. From diffusion and osmosis to active transport, discover how these microscopic gateways keep every cell in balance. ⚡🧫