Describe, using the fluid mosaic model, the structure of the cell membrane in animal cells.

The cell membrane is composed of phospholipid molecules. These have a hydrophobic head and a hydrophilic tail. The molecules arrange themselves in a bilayer so that the hydrophobic heads point outwards and the hydrophilic tails point inwards. This creates the phospholipid bilayer.In between phospholipid molecules there are cholesterol molecules. These maintain membrane fluidity.There are also ion channels which allow molecules unable to diffuse through the membrane directly to entry/exit the cell.Glycoproteins extend from the cell surface and these are complex proteins involved in cell-to-cell recognition.