Picture of Gram +ve bacterial cell wall. The image above is 400 pixels across and the original is 2,000 pixels across.
The Gram positive cell wall has a thick peptidoglycan (orange red in this picture) layer outside the plasma membrane. There may be a gap or periplasmic space between the peptidoglycan layer and the plasma membrane. Various membrane proteins can be seen floating in the plasma membrane. Elongate molecules called teichoic acids intermesh with the peptidoglycan layer. Some of the teichoic acid molecules have a lipid portion (and are called lipoteichoic acids) which binds the molecules to the underlying plasma membrane. In this diagram, the outer aspect of the wall is covered in a regular arrangment of proteins called an S-layer. A good example of an S-layer is shown in our diagram of anthrax.