polysaccharides Flashcards
what are 3 examples of polysaccharides
starch
glycogen
cellulose
what types of chains are there in polysaccharides
branched or unbranched
folded
straight or coiled
what are the 2 types of starch
amylose
amylopectin
what % of starch is amylose
10-30%
what % of starch is amylopectin
70-90%
what are the properties of amylose
- unbranched helix shaped chain with 1,4 glycosidic bonds between alpha glucose molecules
- shape allows it to be compact and more resistant to digestion
what are the properties of amylopectin
- 1,4 with 1,6 glycosidic bonds every 20-30 monomers create a highly branched molecule
- more efficient hydrolysis
is glycogen found in animals or plants
animals
what type of glucose makes glycogen
alpha
what is the structure of glycogen
There are 1,4 glycosidic bonds between α-glucose molecules and also 1,6 glycosidic bonds every 10 monomers creating a branched molecule
what type of glucose makes cellulose
beta
what is the structure of cellulose
- long chains of β-glucose joined together by 1,4 glycosidic bonds
- β-glucose is an isomer of α-glucose, so in order to form the 1,4 glycosidic bonds consecutive β-glucose molecules must be rotated 180° to each other
what gives cellulose its strength
the inversion of the β-glucose molecules means many hydrogen bonds form between the long chains giving cellulose its strength
what is the function of polysaccharides
storage and strength
why are starch and glycogen used for storage
because they’re compact so large quantities can be stored and they’re insoluble so they have no osmotic effect
how is starch stored
as granules in plastids such as amyloplasts and chloroplasts
what is the function of glycogen
storage molecule in animals and fungi
where is glycogen found in high concentrations and why
liver and muscle cells because their cellular respiration rate is high
what is the function of cellulose
structure
strength/ support
cellulose fibre are freely permeable so solutes can pass through to the membrane
