Teichoic acids

 Teichoic acids are polymers of glycerol or ribitol joined by phosphates and are found in the cell walls of gram-positive bacteria.

Teichoic acids consist of lipoteichoic acids (LTAs) and wall teichoic acids (WTAs). WTAs enable the bacterial cell to bind to metal cations outside the cell, such as Ca2+. This is said to affect the repulsion between neighbouring phosphate groups by decreasing the negative charge repulsion caused by the negatively charged oxygen present. By doing so, the WTAs alter the cell walls integrity without influencing the pH gradient in the cell wall.