A disaccharide is formed when two alpha-glucose molecules combine through a condensation reaction, removing a water molecule in the process.
Hydrolysis and condensation reactions are controlled by enzymes
Amylose is a straight-chain molecule made of alpha-glucose units, it forms 80% of starch.
The chain tends to curl up into a helix, the shape of which is held by the formation of hydrogen bonds.
Iodine turns blue-black when we test for starch because the iodine molecules become fixed in the centre of the amylose helix
Cellulose is made of straight chains (1,4) that connect to create strong microfibrils in plant cell walls through hydrogen bonds, providing strength and rigidity.
Amylase can't break ß-glycosidic bonds; only the cellulase enzyme can do that.
polysaccharide - a complex carbohydrate composed of a chain of monosaccharides joined together by glycosidic bonds. e.g., starch, glycogen, cellulose.
All polysaccharides are formed by repeated condensation reactions between sugars
Polysaccharides are insoluable in water and don't form crystals
