A second enzyme, phosphoglucan, water dikinase (PWD) phosphorylates the glucose molecule at the C-3 position.A loss of these enzymes, for example a loss of the GWD, leads to a starch excess (sex) phenotype, and because starch cannot be phosphorylated, it accumulates in the plastids.The biggest industrial non-food use of starch is as an adhesive in the papermaking process.Starch can be applied to parts of some garments before ironing, to stiffen them. "Amylum" for starch is from the Greek ἄμυλον, "amylon" which means "not ground at a mill".It is processed to produce many of the sugars used in processed foods.Mixing most starches in warm water produces a paste, such as wheatpaste, which can be used as a thickening, stiffening or gluing agent.
In industry, starch is converted into sugars, for example by malting, and fermented to produce ethanol in the manufacture of beer, whisky and biofuel.
In the EU this was around 8.5 million tonnes, with around 40% being used for industrial applications and 60% for food uses, Most green plants use starch as their energy store.
An exception is the family Asteraceae (asters, daisies and sunflowers), where starch is replaced by the fructan inulin.
It consists of two types of molecules: the linear and helical amylose and the branched amylopectin.
Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight.