In the Fungi it is usually composed of a modified form of cellulose known as fungus cellulose, which, according to Mangin, consists of callose in combination either with cellulose or pectic compounds.
The sap in these active tissues is alkaline, which has been interpreted as being in accordance with not appear to be concerned with digestion so directly as the others is pectase, which forms vegetable jelly from pectic substances occurring in the cell-wall.
Cellulose has an affinity for acid stains, pectic substances for basic stains.
They can be distinguished by their insolubility in cupramfnonia, which dissolves cellulose, and by their behaviour towards stains, some of which stain pectic substances but not cellulose.
With reference to their chemical physiology, the gelatinization of the cell-wall, which is so marked a feature, is doubtless attributable to the occurrence along with cellulose of pectic compounds.
Cell Membrane.The membrane which surrounds the protoplasts in the majority of plants is typically composed of cellulose, together with a number of other substances which are known as pectic compounds.
Kolb, is that a peculiar fermentation is set up under the influence of heat and moisture, resulting in a change of the intercellular substance - pectose or an analogue of that body - into pectin and pectic acid.