Carbohydrates

• Macromolecules are large molecules made of many repeating smaller units.
• Monomers are joined by condensation and polymers are separated by hydrolysis.
• Condensation reaction is when a water molecule is removed as a bond is formed between the reacting molecules.
• Monosaccharides are the simplest carbohydrates and are made up of one sugar unit.
• Monosaccharides are sweet, soluble and crystalline.
• Disaccharides are formed by the condensation of two monosaccharides.
• Disaccharides are sweet, soluble and crystalline.
• Polysaccharides are formed by the condensation of many monosaccharides.
• Polysaccharides are unsweet, insoluble and not crystalline.
• Alpha Glucose

  
• Beta Glucose

  
• Galactose

  
• Fructose

  
• Fructose

  
• Disaccharides have glycosidic bonds between two monosaccharides.
• Glycosidic bond is a covalent bond between two monosaccharides
• Alpha Glucose + Alpha Glucose = Maltose + Water

  1, 4 glycosidic bond.

  
• Galactose + Alpha glucose = Lactose + Water

  1, 4 glycosidic bond.

  
• Lactose intolerance is a condition where the body cannot break down lactose to lack of enzyme lactase.
• Alpha glucose + Fructose = sucrose

  1, 2 glycosidic bond

  
• Hydrolysis is the chemical breakdown of a compound due to reaction with water.
• Starch is made up of amylose and amylopectin.
• Amylose is a long, unbranched chain of Alpha glucose molecules joined by 1, 4 glycosidic bonds.

  Angle in bond form a helix.
• Amylopectin is a branched chain of Alpha glucose joined by 1, 4 glycosidic bonds and 1, 6 glycosidic bonds.
• Why starch is a good storage molecule:

  • Compact due to branches and helixes so larch amount of glucose units can be stored in a small space.
  • Insoluble so does not cause osmotic effect and cannot leave the cell easily.
  • Many branches so allow faster hydrolysis.
• Glycogen is Alpha glucose molecules joined by 1, 4 glycosidic bonds and 1, 6 glycosidic bonds, but glycogen branches more frequently and is more compact than amylopectin.