Carbohydrates

• Carbohydrates

  • Contain C,H,O
  • Monosaccharides make up carbohydrates; glucose, galactose, fructose
• What bond is created when two monosaccharides are joined?

  Glycosidic through a condensation reaction
• Glucose

  • Hexose sugar - has 6 carbon sugars
  • Two types: Alpha, Beta - these are isomers

  
• Disaccharide

  • 2 monosaccharide joined by a condensation reaction forming a glycosidic bond
  • Sucrose, lactose, maltose
• Maltose


  a-glucose + a-glucose
• Sucrose


  Glucose + fructose
• Lactose


  Glucose + Galactose
• Polysaccharides


  formed when from many glucose units joined together via condensation reactions
• Glycogen


  Condensation of 2 a-glucose on the 1,4 and 1,6 glycosidic bonds

  This is the main energy storage in animals.
• How is Glycogen adapted for energy storage in animals?

  It has a large number of side branches meaning that energy can be released quickly as enzymes can act simultaneously on these branches.

  Moreover, it is relatively large but compact meaning the amount of energy stored can be maximised.

  It is insoluble meaning it will not affect the water potential of the cell and it cannot diffuse out of the cell
• Starch

  • Made from the condensation of two a-glucose
  • Used for storage of energy in pants
  • Mixture of 2 polysaccharides; amylase and amylopectin
• Starch properties that make it good for storing energy

  Amylose

  • Unbranched chain of glucose molecule, this is coiled which means its very compact and stores a lot of energy

  Amylopectin

  • Branched and long, this allows for the side branches to broken down simultaneously by enzymes allowing for quick release of energy

  Insoluble - does not affect the water potential of the cell and can’t
• Cellulose

  • Made from the condensation of b-glucose
  • Used in plant cell walls
• How is cellulose adapted to its function?

  Made from long, unbranched chains of b-glucose.

  Microfibrils are strong threads which are made of long chains running parallel to one another that are joined together by H-bonds forming string cross linkage.

  Stops the cell from bursting under osmotic pressure. It exerts inward pressure that stops the influx of water. This means that calls stay turgid and rigid helping maximise the SA of the plant during photosynthesis