Abstract Hydrogen bonds with a double minimum proton potential show large proton polarizability due to shifts of the proton. Particularly large proton polarizabilities are observed due to the collective motion of the protons within hydrogen-bonded chains. This result was demonstrated by experimental and theoretical treatments. The proton polarizability of hydrogen bonds is indicated by continua in the IR. Hydrogen-bonded chains with this property are very effective proton pathways since they may conduct protons within picoseconds. It is demonstrated that in the L 550 intermediate of bacteriorhodopsin such a pathway is present which conducts protons from the active site to the outside of the membrane. Furthermore, it is demonstrated that in the F 0 subunit a pathway with such properties is present. These pathways are discussed in detail.