Rasvakalvo
Rasvakalvo, commonly referred to as the lipid bilayer, is the fundamental structure of biological membranes in cells and organelles. It is formed by two layers of amphipathic lipid molecules, mainly phospholipids, with hydrophilic heads facing the aqueous environment and hydrophobic tails facing inward. This arrangement creates a semi-permeable barrier that separates the interior of the cell or organelle from its surroundings and defines membrane boundaries.
The bilayer includes other lipids such as cholesterol in animal membranes, which modulates fluidity and stability,
Membranes are described by the fluid mosaic model: lipids diffuse laterally within the bilayer, and many proteins
Functions are diverse: they act as selective barriers controlling the movement of ions and molecules, host
Rasvakalvo is thus central to cellular organization, communication, and metabolism.