Carbohydrates

• Classified based on the number of basic units

  • Can be small, simple molecules (eg. glucose)
  • Can be large, complex molecules (eg. starch)
• Monosaccharides: Basic unit of Carbohydrates

  • Glucose
  • Fructose
  • Galactose
  • Single sugar
• Disaccharides:

  • Maltose
  • Sucrose
  • Lactose
  • Two sugar molecules linked
• Polysaccharides:

  • Starch
  • Glycogen
  • Cellulose
  • Many sugar molecules linked
• Disaccharides:

  1. Glucose + Glucose = Maltose
  2. Glucose + Galactose = Lactose
  3. Glucose + Fructose = Sucrose
• Polysaccharides:

  • Many basic units joined together form Large molecules
• Starch:

  • coiled structure
  • energy store
  • plants- leucoplasts
• Glycogen:

  • branched structure
  • energy store
  • animals- muscle and liver
• Cellulose:

  • linear structure
  • structural component
  • plant cell walls
• How to test for Carbohydrates in GLUCOSE:

  • Reagent: Benedict Solution
  • Heat: Yes- at angle, away from people -bubbles and steams
  • Result:
  • blue - negative
  • green/yellow -low positive
  • orange - medium positive
  • red - high positive
• How to test for Carbohydrates in STARCH:

  • Reagent: Iodine Solution
  • Heat: NO
  • Results:
  • yellow/brown - negative
  • blue black - positive
• Ratio of H : O is 2 : 1