Membranes: - Phospholipid Bilayer
- Cell membrane
- Fluid-mosaic model
Membranes need to be flexible and be able to break/fuse easily.
Membranes allow cellular compartments to have different conditions and act as a barrier within a cell.
Major roles of membranes:
- Cell recognition and signalling
- Partially permeable membrane to let substances in and out of the cell
- Keeps everything in the cell together
- Holding the components of metabolic pathways seperate
- Seperating cell components from cytoplasm
- All have a similar structure
- Usually between 7nm and 10nm
- Invisible to light microscopes but visible to electron microscopes
- Many different types of proteins found within double layer
- Formed by a double layer of phospholipids
Phospholipids are made up of a hydrophilic head which loves water and is made of a phosphate group. They also have the hydrophobic end which are fatty acid tails that must stay away from water.