Give two similarities and two differences between the structure of starch and cellulose polysaccharides (4 marks).
Similarities (up to 2 marks, 1 mark each): Both linked by glucose monomers. Monosaccharides are linked by 1,4 glycosidic bonds. Monosaccharides are joined together via condensation reactions. Both polysaccharides can be broken down via hydrolysis reactions. Both are insoluble in water.Differences (up to 2 marks, 1 mark each): Starch involves alpha glucose whereas cellulose involves beta glucose. Starch also contains 1,6 glycosidic bonds whereas cellulose only contains 1,4 glycosidic bonds. Starch forms a coiled/helical structure whereas cellulose forms a linear fibre.
JD
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