starch, cellulose and glycogen⭐️ Flashcards
What are the two forms of starch?
Amylose and amylopectin
Discuss the structure of amylose
Long unbranched chains, angles of glycosidic bonds give it a coiled structure so it can be compact, good for storage. Forms an alpha helix
Discuss the structure of amylopectin
Long branched chain, side branches allow enzymes to hydrolyse the glycosidic bonds easily so glucose can be released quickly
Why is starch good for storage
Insoluble in water so doesn’t affect water potential, doesn’t cause water to enter the cells by osmosis so cells don’t swell. Large so does not move out of cells
Discuss the structure of glycogen
Long branched chains. Loads of side branches to increase surface area so that stored glucose can be released quickly when hydrolysed. It’s compact so good for storage
Discuss the structure of cellulose
Long unbranched chains linked together by hydrogen bonds to form strong fibres called microfibrils which make it strong and provides structural support for cells, such as cell wall. Each adjacent beta glucose is rotated 180 degrees.
What is starch made out of
Alpha glucose
What is glycogen made out of
Alpha glucose
What is cellulose made out of
Beta glucose
Why is glycogen a good store of glucose?
Insoluble so doesn’t move out of cells and doesn’t affect osmosis, highly branched, compact