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Alpha and Beta glucose
Starch and glycogen are made from alpha glycose while cellulose is
made from beta glucose. Beta glucose is similar to alpha glucose
only the position of the OH group is different.
Remember condensation combines molecules and hydrolysis splits
Main storage compound in plants. Starch is actully a mixture of two
compounds, amylose and amylopectin.
Amylose ( helix) 20% of starch
Amylopectin (branched starch) 80%
NB amylase enzymes remove disaccharides from the ends of
amylose and amylopectin. This is why starch is hydrolysed to
maltose, and not directly to glucose.
Can be hydrolysed more quickly than amylose
-glucose molecules joined by 1-4 glycosidic bonds with 1-6
branches every 20-30 monomers
Plants store it then hydrolyse it when they need a supply of energy
Storage compounds need to be insoluble, compact and easily converted
to energy. The large size of amylose and amylopectin molecules means that they are
insoluble, so they don't have an osmotic effect in starch-containing cells. The spiral/branched
structure of molecules means that theyare compact. The glucose in these compounds can
only be released from the ends of the chain. As amylopectin has many branches, it is able to
release glucose more quickly that amylose.
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Same subunits as amylopectin but much more branched
The storage sugar found in animals
Made mostly by the liver & muscles
Stored as granules in the cytoplasmof cells.
Can be quickly hydrolysed when energy supply needed.
Gycogen is the main storage carbohydrate in mammals. It is very similar in structure to
amylopectin, but is even more branched so can be built up and broken down even more
quickly, matching the greater energy demands.…read more