write the introduction about starch structure and derivative

write an introduction part about starch application in biomedicine

Describe the chemical test for starch.

State the name of the molecule that makes up starch polymers.

translate in persian :The structure and composition of starch are responsible for both its physical and chemical properties. The ratio of amylose to amylopectin and the overall structure of starch varies based on the botanical sources, growing climate conditions, geographic location for cultivation and soil type [17]. Starch has A, B and C crystal structures, which is a function of its origin. In general, it has a small granule size and comes in various shapes based on the source [6]. The granule is composed of anhydroglucose units linked by α-1,4 glycosidic bonds to form amylose and amylopectin polymer entities. Amylose is a linear polymer with α-1,4 glycosidic bonds linking the anhydroglucose units with an average molecular weight of 1 × 106 g/mol. It accounts for the amorphous structure in the starch granule. Amylopectin, on the other hand, has a higher molecular weight averaging about 1 × 108 g/mol and linked by short α-1,4 glycosidic bonds with high branching at the α-1,6 positions that account for the crystallinity in starch [6], [23]. The branching of amylopectin polymer creates double helix of approximately 5 nm length in the starch granule that aligns in the crystalline region [24]. The crystalline region is represented by double helices as shown in Fig. 1. X-ray diffraction of the macroscopic view of starch under illuminated light showed a positive birefringence indicated by a maltese cross, demonstrating an arrangement of the macromolecular units represented by a helix in the starch morphology, which disappears upon disruption of the starch granule [8]. This interchanging arrangement of amorphous and crystalline lamellae in the starch granule is responsible for the semi-crystalline nature of starch with a crystallinity ranging from 20 to 45% [24]. Another important component found in starch is phosphorus, a non-carbohydrate component. Phosphorus exists as monoesters of phosphate and phospholipids. Its presence in the starch granule influences the gel strength, lucidity and solubility depending on the macro-polymer with which it bonds [6].

Explain why starch can be commonly found in leaves.