Cell membranes



There are several components to the plasma membrane.

1. Phospholipid.
The phospholipid has a hydrophillic head and a hydrophobic tail. The heads will point towards water while the tails will turn away. The membrane is a bilayer so two layers of phospholipids.


2. Transmembrane proteins
These are usually channel proteins involved in transport that span across the membrane. Trans means across so Transmembrane - across membrane. These proteins are usually involved in transport.


3. Glycoproteins and Glycolipids
These are proteins or lipids with a polysaccharide tail attached. Poly meaning many and Saccharide as in sugar, so a tail of many sugars. Glycolipids are lipids with polysaccharides attached and Glycoproteins are proteins with sugar tails.


The fluid Mosaic Model.
The components of the cell membrane are not fixed - they are fluid and move around, and it is called a mosaic model because it is made up of so many different parts.

Links:
Cell Membranes Tutorial

Activity:
Revision Worksheet Available until 24th October