Karteikarten
AQA biology 10.3 Starch, glycogen and cellulose
Karten in diesem Stapel (26)
- 1what is starch?A polysaccharide
- 2where is it found?many parts of plants
- 3what is it found in the form of?small grains
- 4where can large amounts be found?seeds and storage organs eg potato tubers
- 5what is starch made up of?chains of alpha-glucose monosaccharides
- 6how are these monosaccharides linked?glycosidic bonds
- 7how are these bonds formed?condensation reactions
- 8how is the molecule compact?it winds into a tight coil
- 9what colour does it stain with iodene solution?deep blue
- 10what is the main role of starch?energy storage
- 11how is it suited for this?-insoluble
-compact
-can be hydrolysed - 12why does it help to be insoluble?-doesnt draw water into cells by osmosis
-doesnt easily diffuse out of cells - 13why does it help to be compact?it can be stored in small spaces
- 14why does it help to be hydrolysed?when hydrolised, it forms alpha-glucose which is easily transported and readily used in respiration
- 15where is starch never found?animal cells
- 16which polysaccharide serves the same role but in humans?glycogen
- 17how is glycogen similar to starch?similar structure
- 18what are the two differences in its structure?shorter chains and highly branched
- 19how and where is it stored?-as small granules
-mainly in the muscles and liver - 20why does it help to be made up of smaller chains?can be hydrolysed more rapidly to alpha-glucose
- 21where is glycogen never found?plant cells
- 22how does cellulose deffr from starch and glycogen?its made of monomers of beta-glucose
- 23how does the arrangement of a beta-glucose unit differ to an alpha-glucose?the position of the -H group and the -OH group opn a single carbon atom are reversed
- 24how is a beta-glucose arranged?the -OH group is above the ring
- 25how do you then get glycosidic links?each molecule must be rotated 180 degrees compared to its neighbour
- 26what is the result of this rotation?the --CH(2)OH group on each beta-glucose molecule alternates between being above and below the chain
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- AS - Level AS Biology (unit 2 - 10. the variety of life) Karteikarten am AQA biology 10.3 Starch, glycogen and cellulose, erstellt von Charlotte Hewson am 30/03/2015.
- Erstellt von
- Charlotte Hewson
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