Cell membranes

Function of cell membranes

- Control which substances enter and leave the cell

- Act as barriers that can create separate evnvironments

fluid mosaic model

The arrangement of phospholipds, integrated proteins, glycoproteins and glycolipids.

Why is it called the fluid mosaic model?

Fluid because the phospholipids are constantly moving and mosaic because proteins are scattered through the bilayer

phospholipid bilayer

The centre of the bilayer is hydrophobic, doesn't allow ions and polar molecules through. It allows small non polar molecules through like co2

Intrinsic proteins

Channel proteins and carrier proteins allow large molecules, polar molecules and ions to pass through the membrane.

Peripheral proteins

On the surface of membranes and act sa receptors and allow the cell to detect chemicals from other cells so that they can respond

Glycoproteins

Proteins with carbohydrate attached. Helps with cell signalling and communication

Glycolipids

Lipids with carbohydrate attached. Helps with cell signalling and communication

Cholesterol

Restricts the movement of other molecules in the membrane which decreases the fluidity of the membrane