Starch is a mix of 2 different polysaccharides:1) Amylose: a long chain of α-glucose monomers joined by 1,4-glycosidic bonds. The chain coils in a spiral shape, held together by hydrogen bonds. This shape makes starch well suited to energy storage as it is compact, so takes up little space in the cell, and not very soluble in water, so does not affect the water potential of the cell. 2) Amylopectin: branched chains of α-glucose monomers joined by 1,4-glycosidic bonds and 1,6-glycosidic bonds. The 1,6-glycosidic bonds form the links which make branches.The branches mean there are many glucose molecules accessible on the end of chains which can be easily broken off by hydrolysis for use in respiration. Therefore amylopectin can provide a rapid supply of energy. Branching also makes it compact, it takes up little space in the cell.