How thick is the cell membrane
7nm
Roles of the cell membrane
Controls movement of substances into and out of the cell
E.g. Nutrients, waste products
Semi-permeable
Barrier to water-soluble substances (because of the hydrophobic core)
Allows passage of lipid soluble substances.
Cell signalling
Cell recognition
Cell-to-cell adhesion
Site for enzymes to catalyse reactions
Anchoring for the cytoskeleton
Form H bonds with water for stability
What is a fluid mosaic model?
Phospholipids and protein molecules are able to move about and diffuse sideways within its monolayer (fluid) and the proteins are interspersed / scattered within membrane (mosaic)
Components of the Plasma Membrane
Phospholipids
Cholesterol
Proteins
Glycolipids (carbs + lipids/fats)
Glycoproteins (carbs + proteins)