1. Polysaccharides
Polysaccharides

2. Polymers made of 100’s of monosaccharide units (MUs)
A condensation reaction occurs between each MU and are held together with glycosidic bonds
Molecules can be branched or unbranched
Are insoluble and not sweet to taste
Storage polysacs are folded to give compact molecules
Structural polysacs are coiled or straight chained

3. Polysaccharides Starch: plant storage Glycogen: animal storage
Cellulose: structural support

4. Starch Main carbohydrate food reserve in plants
A polymer made up of many a glucose molecules held together by GLYCOSIDIC BOND
Made of two compounds – amylose and amylopectin

5. Amylose
Long chains of a glucose molecules linked by 1,4 glycosidic bonds
Chains are coiled to form a spiral held in place by hydrogen bonds

6. Amylopectin
Long chains of a glucose molecules linked by 1,4 glycosidic bonds
Has some 1,6 glycosidic linkages giving it a branched structure

7. - no affect on osmotic balance of cell
What makes starch a
good food store?
Compact
for storage
Insoluble
- no affect on osmotic balance of cell
Readily converted into sugar
many side branches

8. Glycogen similar to amylopectin, made up of chains of a glucose
But has many more 1,6 glycosidic side branches

9. Function
Very compact storage molecule found in mammalian liver (and muscles)
Increased branching allows for quick hydrolysis to release glucose
Means very quick energy release

10. Cellulose Made up of long, unbranched chains of b glucose
Individual chains are linked to each other by hydrogen bonds
Overall structure is of long, strong microfibrils
These form layers at different angles to each other, giving high tensile strength

11. CELLULOSE b glucose O HO OH H O HO OH H O HO OH H H OH O O HO OH H O

14. Function Structural polysaccharide in plants
Cellulose cell walls provide high tensile strength to plant cells
H-bonds prevent water entering the molecule
Makes it resistant to hydrolysis from enzymes