membrankomposition

Membrankomposition is the study of the composition and organization of membranes, focusing on the types and proportions of their constituents and how these components are arranged within and across the membrane bilayer. In biological membranes, the primary components are lipids, proteins, and carbohydrates, each contributing to structure and function.

Lipids form the bilayer matrix and include phospholipids, sphingolipids, and sterols such as cholesterol. Their headgroup chemistry, acyl chain length, and degree of saturation determine membrane thickness, fluidity, and curvature. Many membranes display asymmetry between the outer and inner leaflets, influencing interactions with proteins, signaling molecules, and the extracellular environment.

Proteins provide functional capabilities, including transport channels and pumps, receptors, enzymes, and scaffolding for signaling complexes. They are broadly categorized as integral (transmembrane) or peripheral, with some proteins covalently anchored to lipids. The distribution and mobility of these proteins within the lipid matrix affect signaling pathways, transport efficiency, and membrane remodeling.

Carbohydrates occur mainly as glycoproteins and glycolipids on the extracellular face, contributing to cell recognition, adhesion, and signaling. Their patterns add another layer to membrane identity and interactions with the immune system.

Membrankomposition also encompasses organization into microdomains, such as lipid rafts, and the dynamic processes of lateral diffusion and occasional flip-flop of lipids. Techniques like lipidomics, proteomics, cryo-electron microscopy, and fluorescence methods are used to characterize composition and structure. Alterations in membrane composition are linked to development, physiology, and various diseases, and are a focus in both biological and synthetic membrane research.