Organic solvents Alcohol e.g. Ethyl alcohol, Isopropyl alcohol . Disorganize cell membrane lipid structure. . Denatures protein. . Active against Gram-positive bacteria, Gram-negative bacteria and acid-fast bacilli. Uses:
Potent skin disinfectants
Disinfects clinical thermometer
NB: Ethanol is potent at concentration of 70%.
Chemical agents that denature proteins E.g. Acids and alkalies, Quates, Alcohol . Causes conformational alteration of proteins (unfolding of polypeptide chain) resulting in irregular looping and coiling of polypeptide chain. Acids like benzoic acid, citric acid and acetic acid are helpful as food preservatives: extending storage life of food products.
Chemical agents that modify functional groups of proteins and nucleic acids Heavy metals 1. Mercurials : mercuric chloride – limited use because of toxicity.
Organic mercurials – less toxic than inorganic mercuric salts.
Used as antiseptics. E.g. Merthiolate Mercurochrome