starch

• • Starch is the main energy storage material in plants.
  • Cells get energy from glucose and plants store excess glucose as starch.
  • Starch is insoluble in water so it doesn't cause water to enter cells by osmosis, which would make them swell. This makes it good for storage.
• what is starch made of

  mixture of two polysaccharides of alpha-glucose - amylose and amylopectin
• • Amylose is a long, unbranched chain of a-glucose.
  • The angles of the glycosidic bonds give it a coiled structure, almost like a cylinder
  • This makes it compact, so it's really good for storage because you can fit more in to a small space.
• • Amylopectin is a long, branched chain of a-glucose.
  • Its side branches allow the enzymes that break down the molecule to get at the glycosidic bonds easily.
  • This means that the glucose can be released quickly.