Describe the components of starch and their proportions, along with the chemical structure of amylose.

Starch, a polysaccharide found in plants, consists of two main components: amylose and amylopectin. Amylose constitutes approximately 20-30% of starch and is a linear polymer composed of glucose units linked by α-1,4-glycosidic bonds. The chemical structure of amylose features a helical arrangement due to its predominantly unbranched nature. Amylopectin makes up the remaining 70-80% and is branched, containing both α-1,4 and α-1,6-glycosidic linkages. The branching imparts a more complex, tree-like structure. This combination of linear and branched components provides starch with its characteristic semi-crystalline granular form, facilitating efficient storage and retrieval of glucose in plants.