ABSTRACT
Enzymes are large protein molecules which catalyze all inter-related reactions in the living cell. A plant cell wall is arranged in layers, functionally cell wall is divided into three regions, viz., middle lamella (made of pectins), primary cell wall (cellulose, pectic substances) and secondary cell wall (entirely cellulose). Pectin or pectic substances are major chemical constituents of wall layers and entire middle lamella, where as in other layers, cellulose is found in good amounts. Most of the fungi and parasitic higher plants penetrate wax layers by means of mechanical force alone. Some pathogen has been found to produce enzymes causing degradation of cuticular wax. Cutinases break cutin molecules and release monomers as well as oligomers from insoluble cutin polymer. Primary and secondary wall consists of a matrix in which a large number of microfibrils are embedded. These microfibrils are like bundles of iron bars in a reinforced concretebuilding. Starch is the main reserve polysaccharide found in plant cells.
