biomembranes
Biomembranes are thin, flexible barriers that enclose cells and organelles, defining compartments and regulating the exchange of matter and information with the environment. They are primarily composed of a lipid bilayer formed by amphipathic phospholipids, with cholesterol and other lipids modulating fluidity and thickness. Membrane proteins, including integral transmembrane proteins and peripheral proteins, perform transport, signaling, and enzymatic roles. Carbohydrates are often attached to lipids and proteins on the extracellular face, forming a glycocalyx involved in recognition.
Most biomembranes follow the fluid mosaic model: lipids diffuse laterally in the bilayer, proteins diffuse within
Biomembranes include the plasma membrane and internal membranes such as the nuclear envelope, endoplasmic reticulum, Golgi
Functions include selective permeability, maintaining ion and pH gradients, and enabling energy conversion and signaling. Transport
Membrane synthesis and maintenance rely on coordinated lipid and protein production in the endoplasmic reticulum and