polysaccharides

polysaccharides

1. two monosaccharides are joined

   • condensation reaction
     • water molecule released

2. starch

   • amylose
     • long, unbranched chain of a-glucose
     • angles of glycosidic bond
       • coiled structure
         • compact
           • good for storage
             • can fit more in a small space
   • amylopectin
     • long, branched chain of a-glucose
     • side branches
       • enzymes that break down the molecule can get to glycosidic bond easier
         • glucose released quickly
   • insoluble in water
     • doesn't affect water potential
       • doesnt cause water to enter cell by osmosis
         • dont swell
           • good for storage
   • iodine test
     • add iodine dissolved in potassium iodide solution to test sample
       • positive result
         • browny/orange - blue/black

3. glycogen

   • in animals
   • long, VERY branched chain of a- glucose
     • enzymes that break down the molecule can get to glycosidic bond easier
       • glucose released quickly
         • important in animals
   • compact
     • can fit more in a small space
       • good for storage

4. cellulose

   • long, unbranched chain of of B- glucose
   • beta glucose molecule bond
     • form straight cellulose chains
       • cellulose chains linked by hydrogen bonds
         • weak
           • rong when here are many
         • form strong fibres
           • microfibrils
             • collective group of micro fibrils
               • macrofirbils