In this episode, we cover the plasma membrane, a critical component of all cells, which serves as a semi-permeable barrier regulating the entry and exit of substances. The plasma membrane is primarily composed of a phospholipid bilayer, embedded with proteins and sugars, which contribute to its dynamic ”fluid mosaic” structure. We discuss the roles of integral and peripheral proteins in transport, signaling, and communication, as well as the distinction between passive and active transport mechanisms. Additionally, we cover the importance of saccharides in cell identification and immune response, and the function of plasmodesmata in plant cells for intercellular communication. Understanding the plasma membrane’s structure and functions is essential for grasping the fundamental processes of life.