Fluid Mosaic Model

What is the currently accepted model of the cell membrane?

The fluid mosaic model.

How do phospholipids behave in the fluid mosaic model?

They can move within the bilayer, making the membrane fluid (change shape and flow)

What does the term 'mosaic' refer to in the fluid mosaic model?

The diverse collection of molecules that make up the membrane.

What are three functions of membrane fluidity?

• Formation of vesicles

• Endocytosis and exocytosis

• Movement of transport proteins

What role does cholesterol play in membrane fluidity?

It regulates the fluidity of the membrane.

Fluid mosaic model

A

Phospholipid bilayer shown with heads facing in opposite directions.

B

Phospholipids with labelled hydrophilic/phosphate head and hydrophobic/hydrocarbon tail

C

Peripheral protein, shown as globular structure at the surface of the membrane

D

Integral protein shown as embedded globular structure

E

Glycoprotein shown as an embedded globular structure with protruding carbohydrate branches.

F

Channel protein shown with a pore passing through it.

G

Cholesterol is located between adjacent phospholipids.

H

Glycolipid (in green but unlabeled)