carbohydrates

• Monomers that make up carbohydrates are called monosaccharides
• Monosaccharides are joined together by glucosidic bonds
• During synthesis a hydrogen atom at one monosaccheride bonds to a OH group on the other releasing a molecule of water. Condensation reaction
• Hydrolysis - when a molecule of water reacts with a glycosidic bond breaking it apart
• Dissacharide is formed when 2 monosaccharides are joined together
• A-glucose + fructose = sucrose
• 3 monosaccherides:

  1. alpha glucose
  2. beta glucose
  3. ribose
• 3 dissacherides:

  • lactose
  • maltose
  • galactose
• a-glucose + a-glucose = maltose
• a-glucose + galactose = lactose
• 3 polysaccharides:

  • Starch
  • cellulose
  • glycogen
• starch - the main energy storage material in plants

  1. cells get energy from glucose. plants store excess as starch
  2. starch is a mixture of2 polysaccharides of a-glucose, amylose and amylopectin
  3. starch is insoluble in water so doesn't cause water to enter cells by osmosis. makes them good for storage
• glycogen- main energy storage material in animals

  1. animal cells get energy from glucose. animals store excess as glycogen
  2. structure similar to amylopectin but has a lot more side branches which means that it stored glucose
  3. very compact molecule so good for storage
• cellulose - major component of cell walls in plants

  1. made of long, unbranched chains of b- glucose
  2. when beta glucose molecules bond they form straight cellulose chains
  3. cellulose chains are linked together by hydrogen bonds to form microfibrils. the strong fibres mean cellulose provides structural support for cells
• amylose - long, unbranched chain of a-glucose.

  • angles of glycosidic bonds give it a coil structure.
  • makes it compact so its really good for storage because you can fit more in a small space

  
• AMYLOPECTIN - long branched chain of a- glucose.

  • side branches allow enzymes that break down the molecule to get at the glycosidic bonds easily
  • means glucose can be released quickly

  
• ........... ......

  A) alpha glucose

  
• ...... ......

  A) beta glucose

  
• ...... .....

  A) ribose