Starch

Starch is an organic structure (carbohydrate) composed of two distinct polymers, amylose and amylopectin that are all made up of repeated glucose molecules. It is used as a reserve of energy, providing plants with glucose molecules (and consequently energy) when photosynthesis can not occur (at night or in winter). In humans it's a source of glucose necessary for energy production. Starch is also used in papermaking, glue and laundry.